Targets for use in laser desorption / mass spectrometry

Abstract

A target (110) for use in a laser desorption mass spectrometry apparatus is disclosed. The target (110) has at least one surface (112) that is at least partially covered by at least one layer (114), the layer (114) being a hydrogen-containing, silicon-embedded amorphous carbon (aC:H:Si) layer (116), the aC:H:Si layer (116) being ● 40 atomic % to 80 atomic % carbon; ● 1 atomic % to 20 atomic % hydrogen, and ● 10 atomic % to 40 atomic % silicon Includes.

Description

Technical Field

[0001] The present invention relates to a target for use in a laser desorption mass spectrometer, the use of the target, a laser desorption mass spectrometer, a continuous laser desorption mass spectrometry system, a method for preparing at least one sample for analysis in a laser desorption mass spectrometer, and a method for detecting at least one analyte in a sample by a laser desorption mass spectrometer. The devices and methods can be applied to measure the mass of an analyte or the mass of a fragment of an analyte for the purpose of identification and quantification of the analyte. Specifically, the devices and methods can be applied to quantitative analysis of biological molecules such as proteins, peptides, oligonucleotides, and small molecule compounds. However, other applications are also possible.

Background Art

[0002] In mass spectrometry, matrix-assisted laser desorption / ionization (MALDI) is an ionization technique that uses a laser energy-absorbing matrix to generate ions from large molecules with minimal fragmentation. This is generally applied to the analysis of biological molecules and various organic molecules, which tend to be fragile and fragmented when ionized by more conventional ionization methods. The MALDI method is generally a three-step process. First, the sample is mixed with an appropriate matrix material and applied to a metal plate. Second, a pulsed laser irradiates the sample, causing ablation and desorption of the sample and matrix material. Finally, the analyte molecules are ionized by being protonated or deprotonated in the hot plume of the ablated gas. Thereafter, they can be accelerated to a mass spectrometer for analysis.

[0003] A variation of this technique is the surface-assisted laser desorption / ionization (SALDI) process. Surface-assisted laser desorption / ionization is a soft laser desorption technique used in mass spectrometry. In its first embodiment, Koichi Tanaka used a cobalt / glycerol liquid matrix, and subsequent applications have included graphite / glycerol liquid matrices and solid porous silicon surfaces. Porous silicon represents the first matrix-free SALDI surface analysis, enabling the easy detection of intact molecular ions. Since then, numerous different surfaces have been reported to function as SALDI substrates with varying degrees of success. Based on elemental composition, most SALDI substrates reported in the literature can generally be classified into three main types: carbon-based, semiconducting, and metallic.

[0004] SALDI processes using inorganic matrices for preparation have been described in several studies. Law, Anal.Bioanal.Chem.2011,399,2597,DOI 10.1007 / s00216-010-4063-3 describes recent advances in SALDI-MS technology and their chemical and bioanalytical applications. Based on Law et al., matrix-free devices may meet the following conditions: First, the laser desorption / ionization performance must be much higher than that of direct laser desorption. Polished metal or silicon surfaces can serve as experimental controls. Second, the laser fluence required to achieve laser desorption / ionization should be less than or equal to the normal operation of conventional MALDI using organic matrices. Third, as it is a soft ionization technique, molecular or quasi-molecular ions of the analyte should dominate the mass spectrum. Fourth, if fragmentation occurs, the fragmentation pattern must be regular and predictable. Fifth, a wide range of compounds should be analyzed by this technique.

[0005] A common problem with organic matrices is that the sample and matrix components must dry after being combined in a liquid solution, resulting in the need for cocrystallization. The resulting ionic species of organic matrix-assisted laser desorption are protonated species [M+H]. + In contrast, inorganic matrices are mostly composed of metallized species, such as [M+Na] + This provides a result that is largely driven solely by heat transfer from the matrix to the analyte, and therefore, cocrystallization is generally not necessary.

[0006] Coatings containing amorphous diamond-like carbon materials, applicable to SALDI mass spectrometry, have been described in several studies.

[0007] In Kosyakv et al., J.Anal.Chem.2016,71,1221,DOI 10.1134 / S1061934816130086, a simple and rapid approach is proposed for obtaining target plates for the investigation of low molecular weight compounds by surface-assisted laser desorption / ionization (SALDI) mass spectrometry. This consists of vacuum sputtering of a carbon layer with a thickness of approximately 50 nm onto a metal surface. The resulting coating is characterized by uniformity, hydrophobicity, and high mechanical strength, eliminating the possibility of contamination of the mass spectrometer. A comparison of SALDI mass spectra of test compounds recorded using conventional carbon materials and carbon nanocoatings demonstrates the advantages of the latter material, such as high spectral resolution and the absence of spectral interference at low m / z values.

[0008] Bonn et al., Analyz. Chem. 2008, 80, 7467, DOI 10.1021 / ac801190e, describe the use of nanostructured diamond-like carbon coated digital multi-purpose disks as matrix-free targets for laser desorption / ionization mass spectrometry. The numerous vacancies, defects, and relative sps of DLC films are discussed. 2The carbon content and nanotubes support the LDI phenomenon. The observed DLC absorption rate is in the range of 305–330 nm (nitrogen laser, 337 nm). Universal applicability is demonstrated by different analytes such as amino acids, carbohydrates, lipids, peptides, and other metabolites.

[0009] International Publication No. 2005 / 104180 describes the use of diamond / non-diamond materials, such as diamond / non-diamond carbon material composites or compositions, for chemical or biological analysis. Furthermore, the use of this material in the separation, adhesion, and detection of chemical or biological samples is described. Applications of this material, whether as structured substrates or mixed-phase particles, include, but are not limited to, processes involving the desorption-ionization of samples, more specifically, mass spectrometry.

[0010] International Publication No. 2005 / 096346 describes a target for laser desorption / ionization mass spectrometry, comprising a substrate at least partially coated with a carbon-containing layer containing a material selected from the group consisting of diamond, amorphous carbon, DLC (diamond-like carbon), graphite, nanotubes, nanowires, fullerenes, and mixtures thereof.

[0011] U.S. Patent Application Publication No. 2002 / 0187312 describes an apparatus for providing an ionized analyte for mass spectrometry by photon desorption, comprising at least one layer for contact with an analyte and a substrate on which the layer is deposited. When the apparatus is irradiated, the analyte is desorbed and ionized for analysis by mass spectrometry. One or more layers of the apparatus include a continuous film, a discontinuous film, or any combination thereof.

[0012] Reichardt et al., Analyst 2014, 139, 2873, DOI 10.1039 / c4an00216d, describe nanostructured weathering steel for matrix-free laser desorption / ionization mass spectrometry and imaging of metabolites, drugs, and complex glycans. Specifically, weathering steel was first used to prepare sample plates for matrix-free laser desorption / ionization mass spectrometry (LDI-MS) of small molecules up to approximately 1500 Da in mass range. The effective UV absorption, thermal conductivity, and porosity of the nanostructured internal rust layer formed during passivation determine the superior performance of LDI-MS for a wide range of different analyte classes. The inexpensive material was evaluated in a range of related analytical applications, from matrix-free detection of serum metabolites, lactose quantification, and lipid analysis in milk, to glycosphing profiling of antibodies and imaging mass spectrometry of brain tissue samples.

[0013] Despite the advantages achieved by the devices and methods described above, several technical challenges still remain.

[0014] Surfaces containing microstructured metal / semiconductor and / or carbon-based structures generally exhibit an inherent problem of poor resistance to mechanical stress. When the microstructure is destroyed, the SALDI effect typically decreases. Therefore, the reuse of these structures after analysis is generally not very practical. Furthermore, the manufacturing processes for such surface modifications generally involve high levels of technical and personal interaction. Large-scale processes for the manufacture of disposable products are generally not very practical.

[0015] The ionization process for constructing pseudomolecular ions during ionization generally depends on the presence of impurities other than the analyte, such as a large excess of Na. + or K + If present, the likelihood of metallized species formation during ionization is usually high. Clean surfaces generally have H +This is necessary to enhance (proton) adducts. This is generally necessary because protonated species fragments are much better in mass spectrometry (formation of analyte decomposition products) and can therefore serve as a measurable form of the analyte for multiple reaction monitoring (MRM) analysis. Some mechanical stress is always applied to clean the surface, which is advantageous as it is to use a surface that can withstand mechanical stress.

[0016] Previously developed surface coatings based on diamond-like carbon (DLC) or different carbon allotropes exhibit specific energy transfer from the surface to the analyte; however, this process is generally not efficient enough to ensure a broader analyte range and provide a small detection limit for the purpose of facilitating quantitative analysis. Therefore, further surface development and modification are necessary to meet the requirements of current analytical problems.

[0017] Issues to be resolved Therefore, it is desirable to provide a target for use in a laser desorption mass spectrometer, a target for use, a laser desorption mass spectrometer, a continuous laser desorption mass spectrometer system, a method for preparing at least one sample for analysis in a laser desorption mass spectrometer, and a method for detecting at least one analyte in a sample by a laser desorption mass spectrometer, which at least partially address the technical challenges described above. Specifically, a surface with good mechanical strength that exhibits good SALDI ion species generation efficiency should be provided. [Overview of the project]

[0018] overview This problem is addressed by a target for use in a laser desorption mass spectrometer, a target for use, a laser desorption mass spectrometer, a continuous laser desorption mass spectrometer system, a method for preparing at least one sample for analysis in a laser desorption mass spectrometer, and a method for detecting at least one analyte in a sample by a laser desorption mass spectrometer, having the features of an independent claim. Advantageous embodiments, which may be implemented individually or in any combination, are described in the dependent claims and throughout the specification.

[0019] In the following context, the terms “have,” “comprise,” or “include,” or any grammatical variations thereof, are used inclusively. Therefore, these terms can refer to both situations in which the entity described in this context has no further features beyond those introduced by these terms, and situations in which one or more additional features exist. For example, the expressions “A has B,” “A has B,” and “A includes B” can both refer to situations in which A has no other elements besides B (i.e., A consists solely of B and exclusively of B), and situations in which entity A has one or more additional elements besides B, such as element C, elements C and D, and even further elements.

[0020] Furthermore, it should be noted that the terms “at least one,” “one or more,” or similar expressions indicating that a feature or element may exist once or more times are usually used only once when introducing each feature or element. In most cases below, when referring to each feature or element, the expressions “at least one” or “one or more” will not be repeated, despite the fact that each feature or element may exist once or more than once.

[0021] Furthermore, where used below, the terms “preferably,” “more preferably,” “particularly,” “more especially,” “specifically,” “more specifically,” or similar terms are used in conjunction with any feature without limiting the possibility of alternatives. Thus, the features introduced by these terms are optional features and are not intended to limit the scope of the claims in any way. The present invention may be carried out by using alternative features as those skilled in the art will recognize. Similarly, features introduced by “in embodiments of the present invention” or similar expressions are intended to be optional features without any limitation with respect to alternative embodiments of the present invention, without any limitation with respect to the scope of the present invention, and without any limitation with respect to the possibility of combining such features with other optional or non-optional features of the present invention.

[0022] In a first aspect of the present invention, a target for use in a laser desorption mass spectrometer is disclosed. The target has at least one surface. The surface is at least partially covered by at least one layer. The layer is an amorphous carbon (aC:H:Si) layer containing hydrogen and incorporating silicon. The aC:H:Si layer is ● 40 to 80 atomic percent carbon, ● 1 atomic% to 20 atomic% hydrogen, ● 10 to 40 atomic percent silicon Includes.

[0023] The total amount of carbon, hydrogen, and silicon can be up to 100%, specifically 100%. However, the aC:H:Si layer may contain additional elements. Therefore, the total amount of carbon, hydrogen, and silicon may be less than 100%. Specifically, the total amount of carbon, hydrogen, and silicon can be at least 51%, specifically at least 55%, specifically at least 60%, specifically at least 65%, specifically at least 70%, specifically at least 75%, specifically at least 80%, specifically at least 85%, specifically at least 90%, specifically at least 95%, and specifically at least 98%.

[0024] The aC:H:Si layer may specifically be a hydrogen-containing, heteroatom-modified, silicon-integrated amorphous carbon (aC:H:Si:X) layer. The heteroatom X may be selected from the group consisting of oxygen, nitrogen, fluorine, and boron, and the aC:H:Si:X layer is... ● Up to 15 atomic percent of oxygen, ● Up to 10 atomic percent of nitrogen, ● Up to 10 atomic percent of boron, and ● Up to 5 atomic percent of fluorine It also includes.

[0025] The total amount of oxygen, nitrogen, fluorine, and boron may be at least 1 atomic%, specifically at least 1.5 atomic%, and specifically at least 2 atomic%.

[0026] The total amount of carbon, hydrogen, silicon, oxygen, nitrogen, fluorine, and boron may be specifically 100 atomic percent. However, the aC:H:Si:X layer may also contain additional elements. Therefore, the total amount of carbon, hydrogen, silicon, oxygen, nitrogen, fluorine, and boron may be specifically less than 100 atomic percent. Thus, the total amount of carbon, hydrogen, silicon, oxygen, nitrogen, fluorine, and boron may be at least 52 atomic percent, specifically at least 55 atomic percent, specifically at least 60 atomic percent, specifically at least 65 atomic percent, specifically at least 70 atomic percent, specifically at least 75 atomic percent, specifically at least 80 atomic percent, specifically at least 85 atomic percent, specifically at least 90 atomic percent, specifically at least 95 atomic percent, and specifically at least 98 atomic percent. Other heteroatoms may also be achievable. The heteroatoms may be selected from the group consisting of, specifically, metalloids: germanium, antimony, selenium, and tellurium; post-transition metals: aluminum; transition metals: titanium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, iron, cobalt, copper, and silver; and nonmetals: phosphorus, sulfur, chlorine, bromine, and iodine.

[0027] The expression "atomic %" can specifically refer to the representation of the proportion of atoms in a chemical substance. The proportion of atoms can be calculated by dividing the total number of atoms of each element by the total number of atoms in the chemical substance. The result can then be multiplied by 100.

[0028] As used herein, the term “mass spectrometer” is a broad term and should be given its usual, customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to any analytical device configured to determine or measure the mass-to-charge ratio of ions, but is not limited thereto. The measurement results may be presented specifically as a mass spectrum, for example, a plot of intensity as a function of mass-to-charge ratio.

[0029] As used herein, the term “laser desorption mass spectrometer” is a broad term and should be given its usual customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to any mass spectrometer based on ionization techniques using lasers, but is not limited to these. Specifically, the term may refer to a mass spectrometer that uses a medium and a laser to desorb and ionize a sample or part of a sample from the medium. Specifically, the medium may absorb energy from the laser and then transfer that energy to the sample or part of it. The ionization technique is sometimes called a soft ionization technique. Specifically, a laser desorption mass spectrometer may be configured as a surface-assisted laser desorption ionization (SALDI) technique. The SALDI technique may include at least three distinct steps. In the first step, the sample may be coated onto a target. In the second step, laser pulses of the laser may be applied to the target, and the target may absorb the laser energy and transfer that laser energy to the molecules of the sample. In the third stage, desorption and ionization may occur, and the potential difference may accelerate the generated ions to the mass spectrometer. Specifically, a laser desorption mass spectrometer may comprise at least one target, at least one laser, and at least one mass spectrometry unit. Further details regarding these components are given below in more detail. As used herein, the term “laser desorption mass spectrometry detection” is a broad term and should be given its usual customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to the process of analyzing a sample using a laser desorption mass spectrometer, but is not limited thereto. Detection may specifically refer to the identification of an analyte in the sample. Detection may be qualitative and / or quantitative. More specifically, laser desorption mass spectrometry detection may also be laser desorption imaging mass spectrometry detection. Laser desorption imaging mass spectrometry detection may include visualization of the spatial distribution of molecules by molecular mass. After collecting a mass spectrum at one spot, the target may be moved to reach another region until the region of the target is scanned.By selecting the peaks in the obtained spectrum that correspond to the target analyte, its distribution across the entire target can be mapped.

[0030] As used herein, the term “target” is a broad term and should be given its usual customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to any article, device, or element that is exposed to or can be exposed to a beam, specifically a laser beam, without being limited thereto. For example, a target may be configured as a solid target having a given shape, such as a flat target disk or wafer having a flat target surface and having, for example, a circular, elliptical, or polygonal shape. Specifically, a target may be exposed to or can be exposed to a laser beam of a mass spectrometer, specifically a laser desorption mass spectrometer. Specifically, a target may be a reusable target. As used herein, the term “reusable target” is a broad term and should be given its usual customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to any target that can be configured to be used two or more times, without being limited thereto. As outlined in more detail below, the preparation of the final sample for analysis in a laser desorption mass spectrometer may include coating a target with at least one sample. After at least one measurement, the target, specifically the surface of the target, may be cleaned, for example, to remove the sample. Subsequently, further samples may be coated onto the target and further measurements may be performed.

[0031] Specifically, the target may have a thickness of 0.2 mm to 1 cm, preferably 0.5 mm to 3 mm. Furthermore, the target may have a thickness of less than 1 cm, preferably less than 3 mm.

[0032] The target may specifically include at least one substrate. The term “substrate” as used herein is a broad term and should be given its usual customary meaning to those skilled in the art, and not limited to any special or customized meaning. Specifically, the term may refer to any flat element, for example, a flat element having a lateral extension exceeding at least 2 times, at least 5 times, at least 10 times, or at least 20 times or more in thickness. The substrate may have any shape. Specifically, the substrate may have a circular, elliptical, or polygonal shape, such as a rectangle or a circle. Furthermore, the substrate may have a strip shape, as will be described in more detail below. However, other shapes may also be realized.

[0033] The substrate may be made of at least one conductive material, or may include at least one layer of at least one conductive material. Specifically, the conductive material may have a sheet resistance of 100 Ω / sq or less, preferably 60 Ω / sq or less. Thus, exemplary, the substrate may be made of at least one conductive material, and the aC:H:Si layer may be deposited on the surface of the substrate.

[0034] Furthermore, exemplary, the substrate may be made of at least one electrically insulating material or at least one conductive material, and at least one layer of at least one conductive material may be deposited on the substrate. Thus, the aC:H:Si layer may be deposited on the surface of the layer of at least one conductive material. Thus, the aC:H:Si layer may form the outermost layer of the target. The layer of at least one conductive material may form an intermediate layer of the target. Furthermore, the target may include a layer structure having at least one aC:H:Si layer and at least one layer of at least one conductive material. Specifically, the layer structure may include multiple layers of at least one conductive material. Multiple layers of at least one conductive material may form an intermediate layer of the target. Furthermore, the layer structure may include one or more layers of at least one electrically insulating material. The layer of at least one conductive material may also be called a conductive contact layer. The surface of the substrate on which the aC:H:Si layer may be deposited or the surface of the layer of at least one conductive material may allow for good bonding of the aC:H:Si layer to the surface of the substrate or the surface of the layer of at least one conductive material. The substrate may, for example, be made of glass, and the conductive material may be indium tin oxide (ITO). Therefore, a glass substrate may include at least one ITO layer, and the aC:H:Si layer may be deposited on the surface of the ITO layer. Furthermore, surface pretreatment of the substrate and / or intermediate layer, specifically plasma treatment, may be performed before the aC:H:Si layer is deposited, specifically to improve the adhesion of the aC:H:Si layer to the substrate.

[0035] Specifically, the substrate may be made of at least part of at least one material, or it may include at least one material selected from the group consisting of glass; steel, specifically stainless steel; aluminum; silicon; germanium titanium; copper; cobalt; chromium; molybdenum; nickel; tungsten; tantalum; graphite; and polymer materials, specifically polyethylene, specifically polypropylene, specifically polycarbonate, specifically polystyrene, specifically polyacrylate. Furthermore, the polymer material may be a conductive polymer material, specifically polyaniline, specifically poly(3,4-ethylenedioxythiophene)polystyrene sulfonate, specifically polypyrrole, specifically polythiophene. Other materials, such as alloys containing at least one of the metals outlined above and at least one further element, may also be feasible.

[0036] As used herein, the term “surface” is a broad term and should be given its usual customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to the entire area that separates any object from the outside, but is not limited to this. Thus, an object may have multiple surfaces. As used herein, the term “layer” is a broad term and should be given its usual customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to a predetermined amount of material deposited on the surface of any element, but is not limited to this. Specifically, a layer may be a coating. A layer may completely cover an object or cover only a portion of it. Specifically, a layer may have an outer extension exceeding at least twice, at least five times, at least ten times, and even at least twenty times the thickness of the outer layer. Specifically, an aC:H:Si layer may have a thickness of 100 nm to 10 μm, preferably 500 nm to 1.5 μm. However, other dimensions may also be achievable.

[0037] As used herein, the term "at least partially covered" is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to a special or customized meaning. Specifically, without limitation, this term can refer to the property of any element that is completely or partially covered by something. Specifically, the surface of any element can be completely or partially covered by something. When the surface is partially covered by something, the covered surface may also be referred to as a surface portion. Further, as used herein, the term "surface portion" can refer to a portion of a surface, particularly a distinct portion. Exemplarily, the term "surface portion" can refer to at least 5%, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% of the surface. However, other embodiments may also be possible. A layer can specifically form a continuous layer that covers a surface portion or even the entire surface of a target, specifically a substrate of the target.

[0038] As used herein, the term "hydrogen-containing, silicon-incorporated amorphous carbon (a-C:H:Si) layer" is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to a special or customized meaning. Specifically, without limitation, this term can refer to an amorphous carbon layer containing hydrogen and silicon. Hydrogen and / or silicon can specifically be embedded or dispersed in the carbon layer without being bonded to carbon by a covalent chemical bond. The a-C:H:Si layer can specifically be an amorphous silicon-incorporated diamond-like carbon layer. Amorphous silicon-incorporated diamond-like carbon can have structural, mechanical, electrical, optical, chemical, and / or acoustic properties similar to diamond. Specifically, amorphous silicon-incorporated diamond-like carbon can be a metastable form of amorphous carbon containing sp 3 hybrid carbon atoms. More specifically, amorphous silicon-incorporated diamond-like carbon can be sp 3 , sp 2, and sp 1 It can exist in three hybrid states. The physical properties of amorphous silicon-embedded diamond-like carbon as described above may originate from the mixing of carbon bonds. Specifically, sp 3 Hybridization, like that of diamond, can possess strong sigma bonds, resulting in high mechanical hardness and chemical inertness. 2 The hybridization may have strong intralayer sigma bonds and weak interlayer van der Waals bonds, as in graphite. The physical properties are sp 3 sp for bonding 2 It can be particularly dependent on the ratio of the bonds.

[0039] As used herein, the term “hydrogen-containing, silicon-embedded, heteroatom-modified amorphous carbon (aC:H:Si:X) layer” is a broad term and should be given its usual customary meaning to those skilled in the art, and not limited to any special or customized meaning. Specifically, the term may refer to an amorphous carbon layer containing hydrogen and silicon, and further containing one or more heteroatoms in addition to hydrogen and silicon. Specifically, the hydrogen, silicon, and heteroatoms may be embedded or dispersed in the carbon layer without being bonded to the carbon by covalent chemical bonds. The aC:H:Si:X layer may specifically be an amorphous heteroatom-modified silicon-embedded diamond-like carbon layer. The term “heteroatom” may refer to any atom other than carbon or hydrogen. As outlined above, heteroatoms are selected from the group consisting of oxygen, nitrogen, fluorine, and boron. However, other heteroatoms may also be realizable. The heteroatoms may be selected from the group consisting of, specifically, metalloids: germanium, antimony, selenium, and tellurium; post-transition metals: aluminum; transition metals: titanium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, iron, cobalt, copper, and silver; and nonmetals: phosphorus, sulfur, chlorine, bromine, and iodine.

[0040] A substrate having a surface at least partially covered by at least one layer containing hydrogen-containing silicon-integrated amorphous carbon (aC:H:Si) is commercially available, for example, from CeWOTec GmbH (Chemnitzer Werkstoff-und Oberflaechentechnik, Chemnitz, Germany). CeWOTec GmbH provides a "Technical Data Sheet for XLC-PURA Coatings" containing the information shown in Table 1 below. The Technical Data Sheet was prepared on January 21, 2016, and the information is provided in German. The following table includes an English translation of the text. [Table 1]

[0041] As further outlined above, the elemental composition of the aC:H:Si:X layer can be defined by 40 to 80 atomic percent of carbon; 1 to 20 atomic percent of hydrogen; 10 to 40 atomic percent of silicon; up to 15 atomic percent of oxygen; up to 10 atomic percent of nitrogen; up to 10 atomic percent of boron; and up to 5 atomic percent of fluorine. As outlined above, the sum of oxygen, nitrogen, fluorine, and boron is at least 1 atomic percent. Therefore, the aC:H:Si:X layer may contain at least 1 atomic percent of one or some or all of the heteroatoms. Specifically, the sum of oxygen, nitrogen, fluorine, and boron may be at least 5 atomic percent, preferably at least 10 atomic percent.

[0042] As outlined above, the aC:H:Si layer contains up to 15 atomic percent of oxygen. Specifically, the oxygen content can vary within the aC:H:Si layer. The closer the region of the aC:H:Si layer is to the target surface, the lower the oxygen content may be. Therefore, within the aC:H:Si layer, the oxygen content can decrease continuously or discontinuously in the direction perpendicular to the target surface, i.e., the surface exposed to laser radiation. In the bulk region of the aC:H:Si layer, the oxygen content may be less than 1 atomic percent, specifically less than 0.1 atomic percent, and more specifically less than 0.01 atomic percent.

[0043] As outlined above, the aC:H:Si layer is an amorphous layer. The term “amorphous layer” as used herein is a broad term, and its usual, conventional meaning should be given to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to any layer made of at least one material lacking long-range order, but is not limited thereto. Thus, the atoms of the material may form irregular patterns and possess only short-range order. However, the material may also have an internal structure made of interconnected structural blocks, which may correspond to the crystalline phases of the material. Specifically, the aC:H:Si layer can be deposited on a target surface by a plasma-assisted surface coating process. Specifically, the plasma-assisted surface coating process may be a plasma-assisted chemical vapor deposition (PA-CVD) process. PA-CVD can be carried out at process temperatures ranging from 100°C to 200°C. The term "plasma chemical vapor deposition" generally refers to a deposition method in which a substrate is exposed to one or more volatile precursors that react and / or decompose on the surface of the substrate to produce a desired deposit. However, other deposition methods may also be feasible.

[0044] Specifically, the aC:H:Si layer can form the outermost layer of the target that can face the external environment of the target. Furthermore, the aC:H:Si layer can form a continuous layer on the surface of the target. Moreover, the structural shape of the surface of the aC:H:Si layer can resemble the shape of the substrate surface. Specifically, on a smooth substrate, the aC:H:Si layer can also form a continuous, smooth surface with only a few defect locations.

[0045] The aC:H:Si layer may have a microhardness of 2 GPa to 50 GPa, preferably 5 GPa to 30 GPa, and most preferably 10 GPa to 25 GPa. However, other values ​​may also be achievable. The term “microhardness” as used herein is a broad term and should be given its usual customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to the hardness of a material when exposed to a low applied load, but is not limited to this. During microhardness testing, a diamond indenter of a specific geometric shape may be applied to the surface of a test specimen using a known applied force, also called a load, such as 2 N. This may produce an indentation of about 50 μm. Specifically, Vickers hardness testing or Knoop hardness testing may be applied for the purpose of determining the microhardness of a material. However, other methods may also be achievable.

[0046] Specifically, the aC:H:Si layer may have a coefficient of friction of 0.01 to 0.3, preferably 0.02 to 0.2, and most preferably 0.03 to 0.15. However, other values ​​may also be achievable. The term “coefficient of friction” as used herein is a broad term and should be given its usual and customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to a dimensionless value representing the ratio of the frictional force between two objects to the force pressing them together, though this is not limited to the coefficient of friction. Specifically, the term may refer to static friction, which can be determined by dry sliding against steel or carbide at temperatures below 100°C.

[0047] In a further aspect of the present invention, the use of a target as described above or below in more detail is disclosed for laser desorption mass spectrometry detection of at least one analyte in a sample.

[0048] As used herein, the term “analyte” is a broad term and should be given its usual customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to any chemical or biological substance or species, such as molecules or chemical compounds, that are to be detected and / or measured. Specifically, the presence, concentration, and / or amount of the test substance in a sample may be detected or measured. Specifically, the analyte may be a biological molecule or polymer. The analyte may be selected from the group consisting of: steroids; specifically ketosteroids, specifically secosteroids; therapeutic agents; detergents; glycosides; peptides; proteins; dyes; ions; nucleic acids; amino acids; metabolites; hormones; fatty acids; lipids; carbohydrates. Furthermore, the analyte may be a molecule characteristic of a particular modification of another molecule, or a substance internalized by an organism, or a metabolite of such a substance, or a combination thereof. However, different types of analytes may also be feasible. The steroid may be selected from the group consisting of progesterone, testosterone, estradiol, androstenedione, cortisol, cortisone, and 21-deoxycortisol. However, other steroids may also be feasible. The therapeutic active substance may be selected from the group consisting of digitoxin, mycophenolic acid, theophylline, lidocaine, digoxin, voriconazole, and 4-hydroxyalprazolam. However, other therapeutic active substances may also be feasible. The analyte may contain permanently positively charged molecules or permanently negatively charged molecules. Furthermore, the analyte may have an isotopic pattern. The analyte may have a molar mass of 6 Da to 10,000 Da, preferably 6 Da to 3,000 Da, most preferably 100 Da to 2,000 Da. Specifically, lithium with a molar mass of 6.9 Da may be desorbed.

[0049] As used herein, the term “sample” is a broad term and should be given its usual customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term can refer to any sample, including, but not limited to, test samples, quality control samples, and biological samples, also called internal standard samples. A sample may comprise one or more analytes of interest. Specifically, a sample may be a liquid sample, particularly a liquid sample containing at least one biological substance. Furthermore, the analytes may be provided in the sample, specifically in a tissue sample or a processed serum sample. A tissue sample may specifically have a slice thickness of less than 500 μm. For example, a sample may be selected from the group consisting of physiological fluids, including blood, serum, plasma, saliva, lens fluid, cerebrospinal fluid, sweat, urine, milk, ascites fluid, mucus, synovial fluid, peritoneal fluid, amniotic fluid, tissue, and cells. A sample may be used directly as obtained from its respective source, or it may be subjected to a pretreatment and / or sample preparation workflow. For example, a sample may be pretreated by adding an internal standard and / or dilution with another solution and / or mixing with a reagent. A quality control sample may be a sample that mimics the test sample and contains known values ​​of one or more quality control substances. The quality control substance may be identical to the analyte of interest, or an analyte that produces an identical analyte of interest by reaction or derivatization, and / or an analyte of known concentration, and / or a substance that mimics the analyte of interest or can otherwise correlate with a specific analyte of interest. An internal standard sample may be a sample containing at least one internal standard substance having a known concentration.

[0050] In a further aspect of the present invention, a laser desorption mass spectrometer is disclosed. The laser desorption mass spectrometer is a) At least one target as described above or further described below, b) at least one laser configured to supply energy to a target such that at least one ion of at least one analyte is generated, c) At least one of a mass spectrometer unit and an ion mobility spectrometer and It is equipped with.

[0051] As used herein, the term “laser” is a broad term and should be given its usual and customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term can refer to any device configured to emit light by an optical amplification process based on stimulated emission of electromagnetic radiation, but is not limited to this. Specifically, a laser may be a pulsed laser. The pulse energy may be in the range of less than 60 μJ, specifically less than 35 μJ. Furthermore, a laser may have a laser repetition rate in the range of 1 kHz to 5 kHz, specifically 2 kHz to 3 kHz. For example, a laser may be configured to produce a laser beam within the UV spectral range. Specifically, the laser wavelength may be in the range of 300 nm to 400 nm. More specifically, a laser may be a neodymium-doped yttrium aluminum garnet laser (Nd:YAG laser) having a wavelength of 355 nm.

[0052] As outlined above, the laser is configured to supply energy to the target such that at least one ion of at least one analyte is generated. Thus, the target can be irradiated with at least one laser beam. The term “irradiate” as used herein is a broad term and should be given its usual customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to the process of exposing an object, specifically the surface of an object, to laser light, but is not limited to this. In particular, a first part of the object, specifically a first part of the surface of the object, may be irradiated with at least one laser beam, while a second part of the object, specifically a second part of the surface of the object, may preferably not be irradiated with at least one laser beam. Specifically, the target may absorb the laser energy and transfer the laser energy to the molecules of the sample, so that desorption and ionization can occur.

[0053] As outlined above, a laser desorption mass spectrometer may further comprise at least one mass spectrometry unit. The mass spectrometry unit may be configured to detect or determine at least one mass-to-charge ratio of at least one ion emitted from a target. As used herein, the term “mass spectrometry unit” is a broad term, and its usual, conventional meaning should be given to those skilled in the art, and not limited to any special or customized meaning. Specifically, the term may refer to, but not limited to, an apparatus configured to detect incoming ions. The mass spectrometry unit may be configured to detect charged particles. The mass spectrometry unit may be at least one electron multiplier, or comprise at least one electron multiplier. The mass spectrometry unit may be configured to determine at least one mass spectrum of the detected ion. As used herein, the term “mass spectrum” is a broad term, and its usual, conventional meaning should be given to those skilled in the art, and not limited to any special or customized meaning. Specifically, the term may refer to, but not limited to, a two-dimensional representation of signal intensity versus mass-to-charge ratio (m / z), where the signal intensity corresponds to the abundance of each ion. The mass-to-charge ratio may refer to the reciprocal of a particular charge. The mass spectrum may be a pixelated image. To determine the resulting intensity of the pixels in the mass spectrum, the signals detected by the mass spectrometry unit within a specific m / z range may be integrated. The mass spectrometry unit may comprise at least one evaluation device. The analyte in the sample may be identified by at least one evaluation device. Specifically, the evaluation device may be configured to correlate a known mass with an identified mass, or it may be configured by a characteristic fragment pattern.

[0054] Furthermore, a laser desorption mass spectrometer may be equipped with at least one vacuum pump. The term “vacuum pump” as used herein is a broad term, and its usual, conventional meaning should be given to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to any device configured to draw gas molecules out of a sealed volume in order to leave a partial vacuum and / or to generate negative pressure, such as pressure below atmospheric pressure. A vacuum pump may be configured to generate a relative vacuum within a volume such as a sealed volume. Negative pressure may be generated by allowing or forcing a gas to flow from the sealed volume into the ambient atmosphere and / or another room or chamber. Specifically, a vacuum pump may be configured to provide a pressure gradient between the sealed volume and the ambient atmosphere, such that the pressure value within the sealed volume may be less than the pressure value of the ambient atmosphere. A vacuum pump may be configured to generate negative pressures below 1500 mbar, such as pressures below 1000 mbar, below 100 mbar, below 90 mbar, below 80 mbar, below 70 mbar, below 60 mbar, below 50 mbar, below 40 mbar, below 30 mbar, below 20 mbar, below 10 mbar, below 5 mbar, below 1 mbar, or less. Specifically, a vacuum pump may be configured to generate negative pressures from 0 mbar to 1500 mbar, specifically from 0 mbar to 1000 mbar.

[0055] A laser desorption mass spectrometer may comprise at least one chamber. A vacuum pump may be configured to generate negative pressure within the chamber. A target may be received within the chamber. Furthermore, a mass spectrometry unit may be received within the chamber. Furthermore, a laser desorption mass spectrometer may comprise at least one field generator. The field generator may be configured to generate an electric field and / or a magnetic field. The electric field and / or magnetic field may be configured to pull the generated ions away from the target.

[0056] Furthermore, the laser desorption mass spectrometer may comprise at least one ion mobility spectrometer having at least one ion mobility spectrometer cell. The term “ion mobility spectrometer” as used herein is a broad term, and its usual and customary meaning should be given to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to any analytical technique configured to separate and identify ionized molecules in a gas phase based on their mobility in a carrier buffer gas. Specifically, the ion mobility spectrometer may be coupled to a laser desorption mass spectrometer to specifically achieve multidimensional separation. The ion mobility spectrometer may be configured to detect at least one drift time of ions passing through an ion mobility spectrometer cell.

[0057] In a further aspect of the present invention, a continuous laser desorption mass spectrometry system is disclosed, comprising at least one laser desorption mass spectrometer as described above or below in more detail. The target is provided as a stack of material strips or platelets.

[0058] As used herein, the term “continuous laser desorption mass spectrometry system” is a broad term and should be given its usual, customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to any desorption mass spectrometry system configured to measure multiple samples sequentially, preferably without interruption of measurement. A continuous laser desorption mass spectrometry system is sometimes simply called a desorption mass spectrometry system.

[0059] As outlined above, the target is provided as a material strip or a stack of platelets. When the target is provided as a material strip, it may specifically be provided in a coil. The material strip may be configured to unwind one or more samples before coating the material strip, particularly the surface of the material strip. The material strip may be configured to pass through a continuous laser desorption mass spectrometer system. Specifically, the material strip may be configured to pass through different stations of the continuous laser desorption mass spectrometer system. The different stations may comprise laser desorption mass spectrometers and may further comprise one or more liquid processing systems and one or more vacuum zones. Further details regarding the liquid processing systems and vacuum zones may be provided in more detail below. The material strip may specifically be made of steel or aluminum. However, other materials may also be feasible. The material strip may have a width of 0.5 cm to 10 cm, preferably 1 cm to 3 cm. Furthermore, the material strip may have a thickness of 0.2 mm to 2 mm, preferably 0.5 mm to 1 mm. Furthermore, the material strip may have a length of 5 m to 100 m. However, other dimensions may also be feasible. Specifically, the length of the material strip may not be limited. More specifically, the material strip may be manufactured by performing a coating on the substrate during the winding process. Thus, exemplary, an aC:H:Si layer may be formed on the surface of the substrate during the winding process. This manufacturing process is sometimes exemplary referred to as a roll-to-roll PA-CVD coating process.

[0060] Furthermore, as outlined above, the target is provided as a stack of platelets. Specifically, the platelets may have a rectangular shape, such as a square. However, other shapes, such as a circle, may also be realized. Specifically, the platelets may have a thickness of 0.2 mm to 1 cm, preferably 0.5 mm to 3 mm. Furthermore, the platelets may have a width ranging from 1 cm to 10 cm, preferably 1 cm to 8 cm, most preferably 1 cm to 5 cm. Furthermore, the platelets may have a length ranging from 1 cm to 15 cm, preferably 1 cm to 12 cm, most preferably 1 cm to 7 cm.

[0061] Platelets may be provided stacked on top of each other. Specifically, a continuous laser desorption mass spectrometer system may include at least one platelet holder configured to receive a stack of platelets. The platelet holder may be configured to continuously discharge the platelets. Specifically, a continuous laser desorption mass spectrometer system may include at least one conveyor belt. The platelet holder may be configured to continuously discharge the platelets onto the conveyor belt. The conveyor belt may be configured to continuously pass platelets through the continuous laser desorption mass spectrometer system. Specifically, the conveyor belt may be configured to continuously pass platelets through different stations of the continuous laser desorption mass spectrometer system.

[0062] Furthermore, a continuous laser desorption / mass spectrometry system may comprise at least one liquid processing system. The liquid processing system may be configured to dispense at least one sample having at least one analyte onto a target, specifically onto a material strip or onto one of a platelet. As used herein, the term “liquid processing system” is a broad term, and its usual and customary meaning should be given to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to any device configured to dispense a liquid, specifically a specified or desired amount of liquid onto another object. The amount of liquid may be adjustable. Specifically, the liquid processing system may comprise one or more pipette units. A pipette unit may comprise at least one chamber configured to hold or receive at least one liquid. The pipette unit may be configured to generate a partial vacuum above the chamber and selectively release the partial vacuum to aspirate and dispense the liquid. Additionally or alternatively, the liquid processing system may comprise at least one acoustic droplet dispensing unit. The acoustic droplet dispensing unit may be configured to move a fluid volume without physical contact using ultrasonic pulses. However, other embodiments may also be feasible.

[0063] Furthermore, a continuous laser desorption / mass spectrometry system may comprise at least one vacuum system. The system may be configured to pass material strips or platelets through the vacuum system. As used herein, the term “vacuum system” is broad and should be given its usual, customary meaning to those skilled in the art, and not limited to any special or customized meaning. Specifically, the term may refer to any device configured to generate a vacuum, a region having a gas pressure lower than atmospheric pressure, within a defined space such as a chamber. For this purpose, the vacuum system may comprise at least one vacuum pump. Further details of the vacuum pump can be found in the description of the vacuum pump above. Specifically, the vacuum system may comprise at least one vacuum zone, preferably at least two vacuum zones. The term “vacuum zone” may refer to a defined space such as a chamber having a gas pressure lower than atmospheric pressure. At least two vacuum zones may be arranged in sequence. A stack of material strips or platelets may be configured to pass through one or more vacuum zones before passing through the vacuum system, specifically the laser desorption / mass spectrometry. The vacuum zone may be configured to provide a negative pressure of less than 1500 mbar, such as pressures of less than 1000 mbar, less than 900 mbar, less than 800 mbar, less than 700 mbar, less than 600 mbar, less than 500 mbar, less than 400 mbar, less than 300 mbar, less than 200 mbar, less than 100 mbar, less than 90 mbar, less than 80 mbar, less than 70 mbar, less than 60 mbar, less than 50 mbar, less than 40 mbar, less than 30 mbar, less than 20 mbar, less than 10 mbar, less than 1 mbar, or less. Specifically, at least two vacuum zones may be configured to provide different negative pressures from each other. Other parameters may also be achievable. The vacuum system, specifically the vacuum zones, may be configured to dry the sample on the target.

[0064] In a further aspect of the present invention, a kit is disclosed.

[0065] As used herein, the term “kit” is a broad term and should be given its usual and customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to a set of several items, such as chemicals, used to carry out a desired method, specifically a sample preparation method and / or a sample analysis method. Specifically, the articles may be contained within a housing, for example, packaging.

[0066] The kit comprises (i) at least one target as described in more detail above or below; and (ii) at least one internal standard.

[0067] As used herein, the term “internal standard” may refer to an analyte present in a sample at a specified concentration. Specifically, the concentration of the internal standard may be known. However, it may also be assumed that the concentration of the standard is unknown but is the same for at least the sample of interest and at least one calibration sample. In such a case, specifically, the concentration of the internal standard may be the same for all samples being analyzed. Specifically, the internal standard may be structurally similar to or identical to the analyte. In particular, the internal standard may be an isotopically labeled molecule, specifically an isotopically labeled version of the analyte, e.g. 2 H (deuterated), 15 N and / or 13 It may be a 1C-labeled derivative. The internal standard sample may be a sample containing at least one known internal standard substance, for example, having a predetermined concentration.

[0068] The kit may optionally include additional elements. These additional elements may be selected from the group consisting of auxiliary reagents, specifically derivatization reagents; and bead suspensions for the purification step.

[0069] In a further aspect of the present invention, a method for preparing at least one sample for analysis in a laser desorption mass spectrometer is disclosed.

[0070] This method specifically includes the following steps, which can be performed in a given order. However, it should be noted that different orders are also possible. Furthermore, one or more method steps can be performed once or repeatedly. Furthermore, two or more method steps can be performed simultaneously or in overlapping order. This method may include further method steps not described herein.

[0071] This method, i. To provide at least one target relating to any one of the embodiments described above or any one of the embodiments described in more detail below, ii. Applying at least one sample to a target, wherein the sample contains at least one analyte. Includes.

[0072] In step ii, the sample may be applied to the target by a liquid processing system, preferably a pipette unit. Further details of the liquid processing system can be found in the description above.

[0073] Furthermore, this method is as follows: iii. Step to dry the sample It may include.

[0074] Step iii may specifically be performed after step ii. Step iii may include air drying of the sample on the target, for example, drying in the open air. Additionally or alternatively, step iii may include drying the sample via at least one vacuum system. Further details of the vacuum system can be found in the description above.

[0075] Furthermore, the method may further include at least one cleaning step. During the cleaning step, the aC:H:Si layer may be cleaned. The cleaning step may be performed before step ii. is carried out.

[0076] Specifically, the cleaning step may refer to the initial cleaning of the target during or after the manufacturing process. More specifically, the cleaning step may be performed after the aC:H:Si layer has been deposited on the target surface by a plasma-assisted surface coating process, etc. Therefore, the cleaning step may include the removal of impurities caused by the deposition process of the aC:H:Si layer. Furthermore, the cleaning step may include the removal of contamination such as dust and dirt that occurs during storage of the target. Initial cleaning after the manufacturing process may improve the visibility of protonated pseudomolecular ions. However, the initial cleaning after the manufacturing process may be optional. A target having an aC:H:Si layer may also be suitable for laser desorption mass spectrometry detection without initial cleaning after the manufacturing process.

[0077] Furthermore, the cleaning step may refer to cleaning the target after its previous application. Therefore, the cleaning step may include the removal of any previously applied samples to the target. Additionally, the cleaning step may include the removal of contamination such as dust and dirt that accumulates during storage of the target. Therefore, the target is sometimes referred to as a reusable target. Further details regarding reusable targets can be found in the description above.

[0078] The cleaning step may specifically involve rinsing or sonicating the aC:H:Si layer with at least one solvent. Specifically, the solvent may be deionized water. Furthermore, the solvent may be an organic solvent, specifically a mixture of organic solvents, specifically a mixture of organic solvents with deionized water. The organic solvent may be selected from the group consisting of tetrahydrofuran, acetonitrile, methanol, and ethanol. However, other organic solvents such as other hydrocarbons or alcohols may also be feasible.

[0079] In a further aspect of the present invention, a method for detecting at least one analyte in a sample using a laser desorption mass spectrometer is disclosed.

[0080] This method specifically includes the following steps, which can be performed in a given order. However, it should be noted that different orders are also possible. Furthermore, one or more method steps can be performed once or repeatedly. Furthermore, two or more method steps can be performed simultaneously or in overlapping order. This method may include further method steps not described herein.

[0081] This method, I. To carry out a method for preparing at least one sample for analysis in a laser desorption mass spectrometer, according to any one of the embodiments described above or any one of the embodiments described in more detail below, II. Detecting at least one analyte in a sample using at least one laser desorption mass spectrometer according to any one of the embodiments described above or any one of the embodiments described in more detail below. Includes.

[0082] The methods and devices according to the present invention offer numerous advantages over known methods and devices.

[0083] This invention presents the use of plasma-assisted surface modification of amorphous carbon (aC:H:Si:X (wherein X=O, N, F and / or B)). The elemental composition of plasma-assisted surface modification of amorphous carbon can be specified in the range of 40 to 70 atomic percent carbon, 1 to 20 atomic percent hydrogen, 15 to 40 atomic percent silicon, up to 15 atomic percent oxygen, up to 10 atomic percent nitrogen, up to 10 atomic percent boron, and up to 5 atomic percent fluorine. This can construct a surface with optimal mechanical strength and may exhibit a very good SALDI ion species generation efficiency compared to unfunctionalized substrates or different surface plasma process modifications. Specifically, substrates that may be made of stainless steel or glass can be modified by the plasma-assisted surface coating process. Gray steel may become brown / gold-like in color and may be slightly iridescent. The target can specifically have a surface microhardness of 10 GPa to 25 GPa. The target may have a coefficient of friction of 0.03 to 0.15. To use the target, the only sample preparation step may be pipetting and air drying to obtain a sufficient MS signal after laser irradiation. Washing the plate first after the manufacturing process may allow or improve the visibility of protonated pseudomolecular ions.

[0084] In summary, without ruling out the possibility of further embodiments, the following embodiments may be conceivable: Embodiment 1: A target for use in a laser desorption mass spectrometer, wherein the target has at least one surface, the surface is at least partially covered by at least one layer, the layer being a hydrogen-containing silicon-integrated amorphous carbon (aC:H:Si) layer (116), and the aC:H:Si layer is ● 40 to 80 atomic percent carbon, ● 1 atomic% to 20 atomic% hydrogen, ● 10 to 40 atomic percent silicon A target that includes this.

[0085] Embodiment 2: The aC:H:Si layer is a hydrogen-containing, heteroatom-modified, silicon-integrated amorphous carbon (aC:H:Si:X) layer, where the heteroatom X is selected from the group consisting of oxygen, nitrogen, fluorine, and boron, and the aC:H:Si:X layer is ● Up to 15 atomic percent of oxygen, ● Up to 10 atomic percent of nitrogen, ● Up to 10 atomic percent of boron, and ● Up to 5 atomic percent of fluorine It further includes, The target according to Embodiment 1, wherein the total amount of oxygen, nitrogen, fluorine, and boron is at least 1 atomic percent.

[0086] Embodiment 3: The target according to Embodiment 1 or 2, wherein an aC:H:Si layer is deposited on the surface of the target by a plasma-assisted surface coating process.

[0087] Embodiment 4: The target according to any one of Embodiments 1 to 3, wherein the aC:H:Si layer has a minute hardness of 2 GPa to 50 GPa, preferably 5 GPa to 30 GPa, and most preferably 10 GPa to 25 GPa.

[0088] Embodiment 5: The target according to any one of Embodiments 1 to 4, wherein the aC:H:Si layer has a coefficient of friction of 0.01 to 0.3, preferably 0.02 to 0.2, and most preferably 0.03 to 0.15.

[0089] Embodiment 6: The target according to any one of Embodiments 1 to 5, wherein the target includes at least one substrate.

[0090] Embodiment 7: The target according to Embodiment 6, wherein the substrate is made of at least one material selected from the group consisting of glass; steel, specifically stainless steel; aluminum; silicon; germanium; titanium; copper; cobalt; chromium; molybdenum; nickel; tungsten; tantalum; graphite; and polymer materials, specifically polyethylene, specifically polypropylene, specifically polycarbonate, specifically polystyrene, specifically polyacrylate, specifically polyaniline, specifically poly(3,4-ethylenedioxythiophene)polystyrene sulfonate, specifically polypyrrole, and specifically polythiophene.

[0091] Embodiment 8: The target according to Embodiment 6 or 7, wherein the substrate is made of at least one conductive material, or the substrate is made of at least one electrically insulating material, and at least one layer of at least one conductive material is deposited on the substrate.

[0092] Embodiment 9: The target according to any one of Embodiments 1 to 8, wherein the target is a reusable target.

[0093] Embodiment 10: A target according to any one of Embodiments 1 to 9, wherein the aC:H:Si layer has a thickness of 100 nm to 10 μm, preferably 500 nm to 1.5 μm.

[0094] Embodiment 11: Use of a target according to any one of Embodiments 1 to 10 for laser desorption mass spectrometry detection of at least one analyte in a sample.

[0095] Embodiment 12: The use according to Embodiment 11, wherein the analyte is selected from the group consisting of steroids, specifically ketosteroids, specifically secosteroids; therapeutic agents; detergents; glycosides; peptides; proteins; dyes; ions; nucleic acids; amino acids; metabolites; hormones; fatty acids; lipids; and carbohydrates.

[0096] Embodiment 13: The use according to any one of Embodiments 9 to 12, wherein the analyte has a molar mass of 6 Da to 10,000 Da, preferably 6 Da to 3,000 Da.

[0097] Embodiment 14: The use according to any one of Embodiments 9 to 13, wherein the analyte comprises a permanently positively charged molecule or a permanently negatively charged molecule.

[0098] Embodiment 15: The use according to any one of Embodiments 9 to 14, wherein the analyte has an isotopic pattern.

[0099] Embodiment 16: The use according to any one of Embodiments 9 to 15, wherein the analyte is provided in the sample, and the sample is selected from the group consisting of physiological fluids including blood, serum, plasma, saliva, lens fluid, cerebrospinal fluid, sweat, urine, lactation, ascites fluid, mucus, synovial fluid, peritoneal fluid, amniotic fluid, tissue, or cells.

[0100] Embodiment 17: The use according to any one of Embodiments 9 to 16, wherein the laser desorption mass spectrometry detection is laser desorption imaging mass spectrometry detection.

[0101] Embodiment 18: A laser desorption mass spectrometer, a) At least one target as described in any one of the prior embodiments relating to a target, b) at least one laser configured to supply energy to a target such that at least one ion of at least one analyte is generated, c) At least one of a mass spectrometer unit and an ion mobility spectrometer and A laser desorption mass spectrometer equipped with the following features.

[0102] Embodiment 19: A laser desorption mass spectrometer is used. d) At least one vacuum pump The laser desorption mass spectrometer according to embodiment 18, further comprising the above.

[0103] Embodiment 20: The laser desorption mass spectrometer according to Embodiment 19, wherein the vacuum pump is configured to generate a negative pressure from 0 mbar to 1500 mbar, specifically from 0 mbar to 1000 mbar.

[0104] Embodiment 21: A laser desorption mass spectrometer according to any one of Embodiments 18 to 20, wherein the laser wavelength is in the range of 300 nm to 400 nm.

[0105] Embodiment 22: The laser desorption mass spectrometer according to any one of Embodiments 18 to 21, further comprising at least one ion mobility spectrometer having at least one ion mobility spectrometer, wherein the ion mobility spectrometer is configured to detect at least one drift time of ions passing through the ion mobility spectrometer.

[0106] Embodiment 23: A continuous laser desorption mass spectrometer system comprising at least one laser desorption mass spectrometer according to any one of Embodiments 18 to 22, wherein the target is provided as a stack of material strips or platelets.

[0107] Embodiment 24: The continuous laser desorption mass spectrometer system according to Embodiment 23, wherein the continuous laser desorption mass spectrometer system further comprises at least one liquid processing system, preferably at least one pipetting unit, wherein the liquid processing system is configured to coat at least one sample having at least one analyte onto a target.

[0108] Embodiment 25: The continuous laser desorption mass spectrometer system according to Embodiment 23 or 24, wherein the continuous laser desorption mass spectrometer system further comprises at least one vacuum system, and the continuous laser desorption mass spectrometer system is configured to pass a material strip or platelet through the vacuum system.

[0109] Embodiment 26: The continuous laser desorption mass spectrometer system according to Embodiment 25, wherein the vacuum system comprises at least one vacuum zone, preferably at least two vacuum zones.

[0110] Embodiment 27: A kit comprising (i) at least one target as described in any one of Embodiments 1 to 10, and (ii) at least one internal standard.

[0111] Embodiment 28: A method for preparing at least one sample for analysis in a laser desorption mass spectrometer, i. To provide a target according to any one of the prior embodiments relating to at least one target, ii. Applying at least one sample to a target, wherein the sample contains at least one analyte. Methods that include...

[0112] Embodiment 29: The method is as follows: iii. Step to dry the sample Methods that further include this.

[0113] Embodiment 30: The method according to Embodiment 28 or 29, wherein step ii comprises a liquid processing system, preferably a pipetting unit, for dispensing a sample onto a target.

[0114] Embodiment 31: The method according to any one of Embodiments 28 to 30, further comprising at least one cleaning step, during which the aC:H:Si layer is cleaned, and the cleaning step is performed before step ii.

[0115] Embodiment 32: The method according to Embodiment 31, wherein the cleaning step includes rinsing the aC:H:Si layer with at least one solvent or sonicating it.

[0116] Embodiment 33: The method according to Embodiment 32, wherein the solvent is deionized water.

[0117] Embodiment 34: The method according to Embodiment 32 or 33, wherein the solvent is an organic solvent, specifically a mixture of organic solvents, specifically a mixture of organic solvents with deionized water.

[0118] Embodiment 35: The method according to Embodiment 34, wherein the organic solvent is selected from the group consisting of tetrahydrofuran, acetonitrile, methanol, and ethanol.

[0119] Embodiment 36: A method for detecting at least one analyte in a sample using a laser desorption mass spectrometer, I. Performing the method for preparing at least one sample for analysis in a laser desorption mass spectrometer as described in any one of the preceding embodiments of the method for preparing at least one sample for analysis in a laser desorption mass spectrometer, II. Detecting at least one analyte in a sample using at least one laser desorption mass spectrometer described in any one of the prior embodiments relating to a laser desorption mass spectrometer. Methods that include... [Brief explanation of the drawing]

[0120] Further optional features and embodiments are disclosed in more detail in subsequent descriptions of embodiments, preferably in conjunction with dependent claims. Here, each optional feature may be implemented independently and in any feasible combination, as will be understood by those skilled in the art. The scope of the present invention is not limited by preferred embodiments. Embodiments are schematically shown in the figures, where the same reference numerals in these figures refer to the same or functionally equivalent elements.

[0121] [Figure 1] Figures 1A and 1B show exemplary embodiments of the target according to the present invention. [Figure 2]This shows an exemplary embodiment of the laser desorption mass spectrometer according to the present invention. [Figure 3] Figures 3A and 3B show two different exemplary embodiments of the continuous laser desorption mass spectrometry system according to the present invention. [Figure 4-1] Figures 4A to 4G show a comparison of the mass spectra of steroid mixtures measured on different targets with different surface coatings at 400 laser intensities, normalized to the highest peak intensity. [Figure 4-2] Figures 4A to 4G show a comparison of the mass spectra of steroid mixtures measured on different targets with different surface coatings at 400 laser intensities, normalized to the highest peak intensity. [Figure 5-1] Figures 5A to 5G compare the mass spectra of steroid mixtures measured on different targets with different surface coatings at 400 laser intensities, normalized to the highest peak intensity with individual expansions in the range of m / z 270 to m / z 405. [Figure 5-2] Figures 5A to 5G compare the mass spectra of steroid mixtures measured on different targets with different surface coatings at 400 laser intensities, normalized to the highest peak intensity with individual expansions in the range of m / z 270 to m / z 405. [Figure 6A] Figures 6A and 6B show the full-scan mass spectra of a steroid mixture measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 380 in the positive ion mode (Figure 6A), with an expansion of the mass range from m / z 240 to m / z 410 (Figure 6B), respectively. [Figure 6B] Figures 6A and 6B show the full-scan mass spectra of a steroid mixture measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 380 in the positive ion mode (Figure 6A), with an expansion of the mass range from m / z 240 to m / z 410 (Figure 6B), respectively. [Figure 7A]Figures 7A and 7B show the full-scan mass spectra of a steroid mixture measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 380 in negative ion mode (Figure 7A), with an expansion of the mass range from m / z 250 to m / z 380 (Figure 7B), respectively. [Figure 7B] Figures 7A and 7B show the full-scan mass spectra of a steroid mixture measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 380 in negative ion mode (Figure 7A), with an expansion of the mass range from m / z 250 to m / z 380 (Figure 7B), respectively. [Figure 8A] Figures 8A to 8D show the full-scan mass spectra of a therapeutic mixture measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 380 in the positive ion mode (Figure 8A), with expanding mass ranges from m / z 135 to m / z 285 (Figure 8B), m / z 315 to m / z 395 (Figure 8C), and m / z 775 to m / z 830 (Figure 8D), respectively. [Figure 8B] Figures 8A to 8D show the full-scan mass spectra of a therapeutic mixture measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 380 in the positive ion mode (Figure 8A), with expanding mass ranges from m / z 135 to m / z 285 (Figure 8B), m / z 315 to m / z 395 (Figure 8C), and m / z 775 to m / z 830 (Figure 8D), respectively. [Figure 8C] Figures 8A to 8D show the full-scan mass spectra of a therapeutic mixture measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 380 in the positive ion mode (Figure 8A), with expanding mass ranges from m / z 135 to m / z 285 (Figure 8B), m / z 315 to m / z 395 (Figure 8C), and m / z 775 to m / z 830 (Figure 8D), respectively. [Figure 8D]Figures 8A to 8D show the full-scan mass spectra of a therapeutic mixture measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 380 in the positive ion mode (Figure 8A), with expanding mass ranges from m / z 135 to m / z 285 (Figure 8B), m / z 315 to m / z 395 (Figure 8C), and m / z 775 to m / z 830 (Figure 8D), respectively. [Figure 9A] Figures 9A to 9D show the full-scan mass spectra of the therapeutic mixture measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 400 in negative ion mode (Figure 9A), with mass ranges of m / z 140 to m / z 265 (Figure 9B), m / z 315 to m / z 350 (Figure 9C), and m / z 744 to m / z 805 (Figure 9D), respectively. [Figure 9B] Figures 9A to 9D show the full-scan mass spectra of the therapeutic mixture measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 400 in negative ion mode (Figure 9A), with mass ranges of m / z 140 to m / z 265 (Figure 9B), m / z 315 to m / z 350 (Figure 9C), and m / z 744 to m / z 805 (Figure 9D), respectively. [Figure 9C] Figures 9A to 9D show the full-scan mass spectra of the therapeutic mixture measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 400 in negative ion mode (Figure 9A), with mass ranges of m / z 140 to m / z 265 (Figure 9B), m / z 315 to m / z 350 (Figure 9C), and m / z 744 to m / z 805 (Figure 9D), respectively. [Figure 9D] Figures 9A to 9D show the full-scan mass spectra of the therapeutic mixture measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 400 in negative ion mode (Figure 9A), with mass ranges of m / z 140 to m / z 265 (Figure 9B), m / z 315 to m / z 350 (Figure 9C), and m / z 744 to m / z 805 (Figure 9D), respectively. [Figure 10]Figures 10A and 10B show the full-scan mass spectra of the therapeutic mixture measured on a purified aC:H:Si surface at a laser energy of 380 in the positive ion mode, plotted against the drift time after IMS separation in 3D (Figure 10A) and 2D (Figure 10B). [Figure 11A] Figures 11A and 11B show expanded mass ranges of the full-scan mass spectra of analytes Triton X-100 (Figure 11A) and PEG1970 (Figure 11B), measured by laser desorption ionization on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 450 in positive ion mode. [Figure 11B] Figures 11A and 11B show expanded mass ranges of the full-scan mass spectra of analytes Triton X-100 (Figure 11A) and PEG1970 (Figure 11B), measured by laser desorption ionization on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 450 in positive ion mode. [Figure 12] This shows an expanded mass range of the full-scan mass spectrum of cyclosporine A between m / z 1150 and m / z 1300, measured by laser desorption ionization on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 450 in positive ion mode. [Figure 13] The full-scan mass spectrum of the permanently positively charged analyte Testosterone-Girard T, measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 380 in positive ion mode, is shown. [Figure 14] This shows a product ion scan of the permanently negatively charged analyte dodecyl sulfate (DC), measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 400 in negative ion mode. [Figure 15A]Figures 15A and 15B show corresponding magnified views of the isotopic pattern of [EY-H]- in the range of m / z 640 to m / z 653 (Figure 15A) and the calculated isotopic pattern of [EY-H]- (Figure 15B). [Figure 15B] Figures 15A and 15B show corresponding magnified views of the isotopic pattern of [EY-H]- in the range of m / z 640 to m / z 653 (Figure 15A) and the calculated isotopic pattern of [EY-H]- (Figure 15B). [Figure 16] The plot of the synthetic intensity ratio Pr / 13C3Pr CIR Pr / 13C3Pr against Pr concentrations c in the range of 10 μg / mL to 10 ng / mL is shown along with a linear regression line, and also with an expanded range from 1.0 μg / mL to 10 ng / mL. [Figure 17] The plot of the composite intensity ratio Es / 13C3Es CIR Es / 13C3Es against Es concentrations c in the range of 10 μg / mL to 10 ng / mL is shown along with a linear regression line, and further expanded to cover the range from 1.0 μg / mL to 10 ng / mL. [Figure 18] This plot shows the total number of [Es-H]- counts against Es concentrations ranging from 10 μg / mL to 10 ng / mL on heteroatom-modified hydrogen-containing carbon surfaces, compared to bare steel and rusted steel. [Figure 19A] Figures 19A and 19B show portions (m / z 330 to m / z 348) of the full-scan mass spectra of [Pr+Na]+ and [13C3Pr+Na]+ obtained from the first SALDI-MS measurement on a heteroatom-modified hydrogen-containing carbon surface with a laser intensity of 450 units (Figure 19A), and the normalized total intensity ratio Pr / 13C3Pr of N=2 [M+H]+ and [M+Na]+ plotted against the number of times the position was used (Figure 19B). [Figure 19B]Figures 19A and 19B show portions (m / z 330 to m / z 348) of the full-scan mass spectra of [Pr+Na]+ and [13C3Pr+Na]+ obtained from the first SALDI-MS measurement on a heteroatom-modified hydrogen-containing carbon surface with a laser intensity of 450 units (Figure 19A), and the normalized total intensity ratio Pr / 13C3Pr of N=2 [M+H]+ and [M+Na]+ plotted against the number of times the position was used (Figure 19B). [Figure 20A] Figures 20A and 20B show full-scan SALDI mass spectra of treated FFPE tonsil tissue samples on a heteroatom-modified hydrogen-containing carbon surface with a tissue background (Figure 20A) and tissue doped with estradiol operating in negative ion mode with a laser intensity of 380 units (Figure 20B). [Figure 20B] Figures 20A and 20B show full-scan SALDI mass spectra of treated FFPE tonsil tissue samples on a heteroatom-modified hydrogen-containing carbon surface with a tissue background (Figure 20A) and tissue doped with estradiol operating in negative ion mode with a laser intensity of 380 units (Figure 20B). [Figure 21] Figures 21A and 21B show the spatial distribution of m / z 381.1 attributed to sucrose [M+K]+ as a result of SALDI imaging experiments on a cross-section of garlic clove on a heteroatom-modified hydrogen-containing carbon surface (Figure 21A), and the spatial distribution of m / z 527.1 likely attributed to dracobin [M+K]+ as a result of SALDI imaging experiments on a cross-section of garlic clove on a heteroatom-modified hydrogen-containing carbon surface (Figure 21B). [Modes for carrying out the invention]

[0122] Detailed description of the embodiment Figures 1A and 1B show exemplary embodiments of the target 110 according to the present invention.

[0123] As shown in Figure 1A, the target 110 has at least one surface 112. The surface 112 is at least partially covered by at least one layer 114. Layer 114 is hydrogen-containing silicon-integrated amorphous carbon (aC:H:Si) 116. Specifically, the aC:H:Si layer 116 may have a thickness t of: 100 nm to 10 μm. The target 110 may specifically comprise at least one substrate 118. The substrate 118 may, exemplary, be made of steel. Surface 112 may be the surface of the substrate 118.

[0124] Figure 1B shows a further embodiment of target 110. The substrate may comprise at least one layer 174 made of at least one conductive material. The layer 174 of at least one conductive material may also be called a conductive contact layer 176. Thus, the aC:H:Si layer 116 may be deposited on the surface 178 of the layer 174 of at least one conductive material. The layer 174 of at least one conductive material may form an intermediate layer, and the aC:H:Si layer 116 may be the outermost layer.

[0125] Figure 2 shows an exemplary embodiment of the laser desorption mass spectrometer 120 according to the present invention.

[0126] The laser desorption mass spectrometer 120 comprises at least one target 110. The target 110 may correspond at least partially to the target 110 as shown in Figure 1. Therefore, refer to the description of Figure 1 above. Furthermore, the laser desorption mass spectrometer 120 comprises at least one laser 122. The laser 122 is configured to supply energy to the target 110 so as to generate at least one ion of at least one analyte. Furthermore, the laser desorption mass spectrometer 120 may comprise at least one mass spectrometry unit 124. The mass spectrometry unit 124 may be configured to detect at least one mass-to-charge ratio of at least one ion emitted from the target 110.

[0127] The laser desorption mass spectrometer 120 may comprise at least one chamber 126. Furthermore, the laser desorption mass spectrometer 120 may comprise at least one vacuum pump 128. The vacuum pump 128 may be configured to generate negative pressure within the chamber 126. The negative pressure may be generated by allowing or forcing a gas flow from the chamber to the ambient atmosphere, schematically indicated by arrow 130. Specifically, the vacuum pump 128 may be configured to generate a negative pressure of less than 1500 mbar.

[0128] Laser 122 may specifically be a pulsed laser 132. Laser 122 may be configured to produce a laser beam within the UV spectral range. Laser 122 may be positioned relative to target 110 such that the laser beam, schematically indicated by arrow 134, strikes target 110 at an angle of 10° to 90°, preferably 30° to 70°. Specifically, target 110 may absorb laser energy and transfer it to molecules in the sample, allowing desorption and ionization to occur.

[0129] Furthermore, the laser desorption mass spectrometer 120 may include at least one mass separation module 136. The setup of the mass separation module 136 may depend on the applicable mass spectrometry technique.

[0130] A mass spectrometer unit 124 having a readout electronic circuit 138 can be housed in a chamber 126. Furthermore, the mass spectrometer unit 124 can be positioned at a certain distance from the target 110. The mass spectrometer unit 124 is configured to detect or determine the mass-to-charge ratio of at least one ion emitted from the target 110.

[0131] Figures 3A and 3B show two different exemplary embodiments of the continuous laser desorption mass spectrometer system 140 according to the present invention.

[0132] The continuous laser desorption mass spectrometry system 140 shown in Figures 3A and 3B comprises at least one laser desorption mass spectrometer 120. The laser desorption mass spectrometer 120 corresponds at least partially to the laser desorption mass spectrometer 120 as shown in Figure 2. Therefore, refer to the description of Figure 2 above.

[0133] Figure 3A shows a continuous laser desorption mass spectrometer system 140 in which the target 110 is provided as a material strip 142. The material strip 142 may be made of steel or aluminum. The material strip 142 may be wound up to a roll 144. The material strip 142 may be configured to be unwound before one or more samples are applied to the material strip 142, specifically to the surface 146 of the material strip 142. The material strip 142 may be configured to pass through the continuous laser desorption mass spectrometer system 140. Specifically, the material strip 142 may be configured to pass through different stations 148 of the continuous laser desorption mass spectrometer system 140. The different stations 148 may comprise a laser desorption mass spectrometer 120 and may further comprise one or more liquid processing systems 150 and / or vacuum systems 152.

[0134] The liquid processing system 150 may be configured to apply at least one sample 168 having at least one analyte to a target 110, specifically a material strip 142. Specifically, the liquid processing system 150 may comprise one or more pipette units 154. Specifically, the liquid processing system 150 may be configured to apply multiple samples 168 sequentially onto different regions 156 of the material strip 142. The different regions 156 may be spaced apart from each other.

[0135] The vacuum system 152 may comprise one or more vacuum zones 158. The vacuum zones 158 may be arranged in a sequence. The material strip 142 may be configured to pass through the vacuum system 152, specifically one or more of the vacuum zones 158, before passing through the laser desorption mass spectrometer 120. Specifically, the material strip 142 may be configured to pass through at least one first vacuum zone 160 and at least one second vacuum zone 162 before passing through the laser desorption mass spectrometer 120. The first vacuum zone 160 may be configured to provide a first negative pressure, and the second vacuum zone 162 may be configured to provide a second negative pressure. The first negative pressure may be higher than the second negative pressure, or vice versa. The first and second negative pressures may be less than 1500 mbar. The vacuum system 152, specifically the vacuum zones 158, may be configured to dry the sample on the target 110. Furthermore, the vacuum system 152 may include at least one third vacuum zone 184 and at least one fourth vacuum zone 186. Specifically, the material strip 142 may be configured to pass through at least one third vacuum zone 184 and at least one fourth vacuum zone 186 after passing through the laser desorption mass spectrometer 120. The third vacuum zone 184 and the fourth vacuum zone 186 may be configured to keep the vacuum in the laser region as low as technically possible, in order to ensure continuous outward movement and, in particular, to ensure reliable measurements.

[0136] The laser desorption mass spectrometer 120 may, for example, be equipped with a quadrupole, followed by ion trapping, isobaric separation by ion mobility, fragmentation in a collision cell, and then quadrupole or time-of-flight (ToF) mass spectrometry. Other ion manipulation techniques such as magnetic sectors or ion traps, and different combinations of corresponding units are also possible.

[0137] Figure 3B shows a continuous laser desorption mass spectrometer system 140 in which the target 110 is provided as a stack 164 of platelets 166. Specifically, the platelets 166 may have a rectangular shape, such as a square. The platelets 166 may be made of steel, glass, or aluminum. However, other materials may also be feasible. The platelets 166 may be provided stacked on top of each other. Specifically, the platelets 166 may be stored in a platelet holder 170. The platelet holder 170 may be configured to continuously discharge the platelets 166. Specifically, the continuous laser desorption mass spectrometer system 140 may include at least one conveyor belt (not shown). The platelet holder 170 may be configured to continuously discharge the platelets 166 onto the conveyor belt. The conveyor belt may be configured to continuously pass the platelets 166 through different stations 148 of the continuous laser desorption mass spectrometer system 140. Specifically, the conveyor belt may be configured to continuously pass the platelets 166 through the liquid processing system 150. After individually collecting the platelets 166 from the stack 164, a sample 168 containing the analyte solution can be loaded onto the platelets 166 by using the pipette unit 154. The sample 168 can be pipetted onto the surface 172 of the platelets 166. Furthermore, the conveyor belt may be configured to continuously pass the platelets 166 through the vacuum system 152 and the laser desorption mass spectrometer 120. Further details of the liquid processing system 150, the vacuum system 152, and the laser desorption mass spectrometer 120 can be found in the description of Figure 3A above. [Examples]

[0138] The following examples serve to illustrate the present invention. They should not be construed as limiting the scope of protection.

[0139] In the following examples, samples containing analytes were prepared. Specifically, the analytes were selected from steroids and therapeutic substances. For some of the following examples, mixtures of seven natural steroids were prepared. The naturally occurring steroids (S) were selected from the group consisting of: progesterone (Pr), testosterone (Te), estradiol (Es), androstenedione (S7), cortisol (S9), cortisone (S10), and 21-deoxycortisol (S19). The concentration of each natural steroid was 14 μg / mL, and the solvent was a mixture of deionized water and acetonitrile (H2O / MeCN = 80 / 20). Furthermore, mixtures of seven therapeutic substances (T) were prepared. The therapeutic substances were selected from the following group: digitoxin (T7), mycophenolic acid (T16), theophylline (T29), lidocaine (T37), digoxin (T41), voriconazole (T62), and 4-hydroxyalprazolam (4OHAlp). The concentration of each therapeutic substance was 14 μg / mL, and the solvent was a mixture of deionized water and acetonitrile (H2O / MeCN = 80 / 20). 4OHAlp was ordered from Enzo Life Sciences Inc. Deionized water was obtained from a Merck KGaA Milli-Q® water purification system, acetonitrile and methanol were ordered from Biosolve BV, and tetrahydrofuran was ordered from Merck KGaA. The remaining chemicals were ordered from Sigma-Aldrich Inc.

[0140] Measurements were performed using a Maldi-Synapt-G2Si mass spectrometer (Waters Inc.), which is capable of quadrupole mass filtering and ion mobility separation. The laser repetition rate was set to 2.5 kHz for imaging experiments and 1.0 kHz for all other measurements, using a 355 nm Nd:YAG laser wavelength. The analyte spot was measured by a 40 Hz linear profile and plate movement during laser irradiation, respectively. The laser intensity could be varied on a relative scale up to 500, similar to the maximum power energy of 30 μJ. Individual voltage settings were set to the following gradient parameters: "sample plate" 0.0 V, "extraction" 10.0 V, "hexapole" 10.0 V, and "aperture 0" 5.0 V, as well as a hexapole RF amplitude of 350 V.

[0141] The mass spectra described in more detail below show the relative abundance ra in percent, depending on the mass-to-charge ratio m / z.

[0142] Example 1 As a first embodiment, the laser desorption and ionization performance of different surface coatings was screened.

[0143] Figures 4A to 4G show a comparison of the mass spectra of steroid mixtures measured on different targets with different surface coatings at 400 laser intensities, normalized to the highest peak intensity.

[0144] Figures 5A to 5G compare the mass spectra of steroid mixtures measured on different targets with different surface coatings at 400 laser intensities, normalized to the highest peak intensity with individual expansions in the range of m / z 270 to m / z 405.

[0145] Different types of targets were tested. The target substrates were all made of steel. The mass spectra shown in Figures 4A and 5A were obtained by utilizing an aC:H:Si:X layer. The targets were coated by plasma-assisted chemical deposition, respectively. The mass spectra shown in Figures 4B and 5B were obtained by utilizing a diamond-like carbon layer (DLC, C≈91 atoms, H≈5 atoms, and Si≈4 atoms). The targets were coated by plasma-assisted chemical deposition, respectively. The mass spectra shown in Figures 4C and 5C were obtained by utilizing an electrostatically dissipative diamond-like carbon layer containing aC:H:Si:N (C≈74 atoms, H≈5 atoms, Si≈2 atoms, and N≈19 atoms). The targets were coated by plasma-assisted chemical deposition, respectively.

[0146] The mass spectra shown in Figures 4D and 5D were obtained using a titanium carbon nitride (TiCN) layer. The targets were coated by physical vapor deposition (PVD), respectively. The mass spectra shown in Figures 4E and 5E were obtained using a titanium carbide / titanium nitride (TiC / TiN) layer. The targets were coated by high-temperature chemical vapor deposition, respectively. The mass spectra shown in Figures 4F and 5F were obtained using a titanium aluminum nitride (TiAlN) layer. The targets were coated by physical vapor deposition, respectively. The mass spectra shown in Figures 4G and 5G were obtained using a titanium nitride (TiN) layer. The targets were coated by physical vapor deposition, respectively.

[0147] Direct spotting of a 1 μL steroid mixture and measurement using the described voltage setting with a laser energy of 400 yielded mass spectra shown in Figures 4A to 4G and 5A to 5G. Figures 5A to 5G show individual magnifications in the range of m / z 270 to m / z 405. As shown in Figures 4A and 5A, the aC:H:Si:X layer demonstrated excellent ability in desorption and ionization of the tested steroid analytes, without revealing its own significant background signal, particularly here. The steroids progesterone, testosterone, androstenedione, cortisol, cortisone, and 21-deoxycortisol all ionized in positive ion mode from the untreated surface of the aC:H:Si:X layer as sodium adducts [M+Na] + It appeared as such. Similarly, as shown in Figures 4E and 4F and 5E and 5F, TiC / TiN and TiAlN also showed some ability in SALDI-MS analysis, with lower intensity compared to heteroatom-modified hydrogen-containing carbon, but mainly as sodium adducts [M+Na]. + This resulted in the formation of several [M+H] + and [M+K] + This not only led to the detection of steroid adducts but also to the formation of the background signal itself. In summary, the high proportion of silicon in the aC:H:Si:X layer was decisive for the significantly superior performance compared to the aC:H:Si:N layer. In contrast, as shown in Figures 4B and 5B, the DLC layer was [S7+Na] + and [Te+Na] + Only trace amounts of desorption and ionization were observed, and other steroid analytes could not be recognized. Therefore, a diamond-like carbon layer with a low silicon content may be applied, but it may not exhibit superior performance. Furthermore, as shown in Figures 4D and 4G and 5D and 5G, TiCN and TiN did not result in any laser desorption and ionization of the analytes.

[0148] Example 2 As a second example, we evaluated the analyte range for SALDI-MS on an aC:H:Si:X layer.

[0149] To ensure the broad applicability of the aC:H:Si:X layer described herein in the desorption and ionization of analytes obtained by ultraviolet laser irradiation, a wide range of low molecular weight compounds were tested. These analytes were selected to represent important therapeutic substances or metabolites, as well as a wide range of different functionalities and molecular weights in both positive and negative ionization modes. Furthermore, the formation of protonated adducts in positive ionization was investigated instead of alkali adduct formation. This will be an important outcome due to the incompatibility of tandem mass spectrometry experiments with some alkali adducts, particularly with steroid analytes.

[0150] To promote the formation of protonated adducts rather than alkali species, the heteroatom-modified hydrogen-containing carbon coating was purified, and the laser energy during SALDI measurements was optimized. Purification of the surface coating was achieved by simply rinsing with a sufficient amount of solvent, such as tetrahydrofuran, deionized water, and acetonitrile, with the aim of reducing the alkali ions absorbed on the surface. Surface-enhanced laser desorption / ionization measurements of a 1 μL pre-dried steroid mixture on the purified heteroatom-modified hydrogen-containing carbon surface coating described herein resulted in the formation of protonated adducts [M+H] of steroids Pr, Te, S7, S9, S10, and S19 in positive ion mode, as can be seen from Figures 6A and 6B. + Preferential formation of estradiol [Es+H-H2O] + This resulted in a laser intensity of 380 at water loss. Figures 6A and 6B show the full-scan mass spectra of a steroid mixture measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 380 units in the positive ion mode (Figure 6A), with an expansion of the mass range from m / z 240 to m / z 410 (Figure 6B), respectively. Several multiple steroid adducts, e.g., m / z 603.4[Te+Pr+H] +Even that could be observed. In addition to protonated species, several small amounts of sodium and potassiumated steroid adducts were also formed.

[0151] Another important aspect relating to the utility of the heteroatom-modified hydrogen-containing carbon coating described herein is, specifically, the laser desorption and ionization of analytes in negative ionization mode. This was also tested after drying 1 μL of a steroid mixture on a purified heteroatom-modified hydrogen-containing carbon surface and initiating measurements by irradiating it with a laser intensity of 380 units. The corresponding full-scan mass spectra and associated range expansions are shown in Figures 7A and 7B. Figures 7A to 7B show the full-scan mass spectra of the steroid mixture measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 380 in negative ionization mode (Figure 7A), with a mass range expansion from m / z 250 to m / z 380 (Figure 7B), respectively. Here, the most abundant signal in negative ionization mode is estradiol [Es-H] - While belonging to the group of steroids, most other steroids were also detected. This result demonstrates the capability of heteroatom-modified hydrogen-containing carbon surfaces for steroid analysis by laser desorption and ionization.

[0152] Further screening of the analyte range was performed using therapeutic-related substances representing various organic functional groups (e.g., acids, amides, amines, glycosides, halides, hydroxyls, aromatics, or heteroaromatic moieties). Therefore, 1 μL of the therapeutic mixture was dried on a purified heteroatom-modified hydrogen-containing carbon surface and measured by laser irradiation at an intensity of 380 units. The resulting full-scan mass spectra and corresponding magnifications are shown in Figures 8A to 8D. Figures 8A to 8D show the full-scan mass spectra of the therapeutic mixture measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 380 units in positive ion mode (Figure 8A), with magnifications in the mass ranges of m / z 145 to m / z 285 (Figure 8B), m / z 315 to m / z 395 (Figure 8C), and m / z 775 to m / z 830 (Figure 8D), respectively. The seven therapeutic substances Alp, T7, T10, T16, T29, T41, and T62 are all protonated adducts [M+H]. + or alkali adduct [M+Na / K] + It was detected in positive ionization mode.

[0153] Furthermore, the laser desorption ionization of this therapeutic analyte mixture on a heteroatom-modified hydrogen-containing carbon surface was investigated using the negative ionization mode. Therefore, 1 μL was pre-dried on a purified heteroatom-modified hydrogen-containing carbon surface and irradiated with 400 units of laser energy. The resulting full-scan mass spectra and corresponding magnifications are shown in Figures 9A to 9D. Figures 9A to 9D show the full-scan mass spectra of the therapeutic mixture measured on a purified heteroatom-modified hydrogen-containing carbon surface at 400 units of laser energy in the negative ionization mode (Figure 9A), with mass ranges of m / z 140 to m / z 265 (Figure 9B), m / z 315 to m / z 350 (Figure 9C), and m / z 744 to m / z 805 (Figure 9D), respectively. In addition to T62, which was detected in trace amounts, all other analytes showed effective laser desorption ionization on the heteroatom-modified hydrogen-containing carbon surface. The resulting ions are generally deprotonated analytes [MH]. -These results indicate that heteroatom-modified hydrogen-containing carbon surfaces enable laser desorption and ionization of a variety of therapeutically relevant analytes in the low molecular weight range, in both positive and negative ionization modes.

[0154] Another important application of the aC:H:Si:X layer is the combination of laser desorption and ionization by ion mobility spectroscopy (IMS), enabling ion generation using the aC:H:Si:X layer described herein, which has ion separation capabilities for IMS. This was also measured using a therapeutic mixture in positive ionization mode as previously, but was further operated in the IMS measurement mode of the Synapt G2-Si mass spectrometer. Nitrogen was used as the drift gas with a wave velocity of 650 m / s and a wave height of 40 V. Figures 10A and 10B show the drift time t after IMS separation in 3D (Figure 10A) and 2D (Figure 10B), respectively. d The full scan mass spectrum of the therapeutic mixture measured on a purified aC:H:Si surface at a laser energy of 380 in the positive ion mode is shown plotted against. Table 2 below provides the ion mobility spectrum data in tabular format. As can be seen from Figures 10A and 10B, the separation of all seven analytes was successfully achieved with a drift time t d Plotting the m / z ratio yielded further useful data. This demonstrates the broad applicability of the aC:H:Si:X surface, even when separation of analyte mixtures is required. [Table 2]

[0155] Further experiments were conducted to demonstrate the applicability of heteroatom-modified hydrogen-containing carbon surfaces even in the presence of analytes covering a wider mass range. Therefore, two substances were selected, each containing polyethylene glycol (PEG) chains with different chain lengths and their corresponding size distributions. The first analyte solution was used to cover the detergent Triton X-100 (10 μg / mL in H2O / MeCN=80 / 20), and the second analyte solution was used to cover PEG1970 (Mp=1970, PDI=1.03, 100 μg / mL in H2O / MeCN=80 / 20). Each solution was separately spotted (1 μL) onto the heteroatom-modified hydrogen-containing carbon surface and allowed to dry. Subsequent SALDI measurements with a laser intensity of 450 units yielded mass spectra as shown in Figures 11A and 11B. Figures 11A and 11B show the expanded mass range of the full-scan mass spectra of analytes Triton X-100 (Figure 11A) and PEG1970 (Figure 11B), measured by laser desorption ionization on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 450 units in positive ion mode. Triton X-100, as shown, exhibited characteristic protonated adduct peaks mainly in the mass range of m / z 400 to m / z 1000. The PEG1970 sample mainly showed sodium adducts [M+Na] + The small amount of potassium adduct species [M+K] is presented. + The size distribution of the PEG1970 samples was mainly localized in the range of m / z 1300 to m / z 2600. This demonstrated the suitability of heteroatom-modified hydrogen-containing carbon surfaces for SALDI analysis across a wide range of low to medium molecular weight analytes.

[0156] An important class of analytes in the low to medium molecular weight range is generally peptides. To test the suitability of laser desorption / ionization measurements on heteroatom-modified hydrogen-containing carbon surfaces, the therapeutically important cyclic peptide cyclosporine A (CsA, 1 μL in MeCN / H2O, 100 μg / mL = 80 / 20) was selected. Each of the resulting mass spectra is shown in Figure 12. Figure 12 shows the expanded mass range of the full-scan mass spectrum of cyclosporine A (between m / z 1150 and m / z 1300), measured by laser desorption / ionization on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 450 in positive ion mode. Cyclosporine A is primarily composed of the sodium adduct [CsA + Na] + This leads to the detection of several potassium adducts [M+K]+ and even a small number of protonated analyte adducts [M+H]. + It was also detected. In CsA, analytically important peptides were successfully detected by SALDI-MS on heteroatom-modified hydrogen-containing carbon surfaces.

[0157] In addition to the successful laser desorption and ionization of the analyte from a heteroatom-modified hydrogen-containing carbon surface, further experiments were conducted to demonstrate the ability to desorb permanently positively charged molecules without requiring further ionization. For this purpose, a solution of testosterone derivatized with Girard T reagent was prepared (TeGT, 10 μg / mL = 80 / 20 in H2O / MeCN), 1 μL of which was spotted onto a heteroatom-modified hydrogen-containing carbon surface and dried. When this cationic analyte was measured by laser irradiation (intensity 380 units), a full-scan mass spectrum was obtained, as shown in Figure 13. Figure 13 shows the full-scan mass spectrum of the permanently positively charged analyte Testosterone-Girard T, measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 380 units in positive ion mode. The main signal is [TeGT-NMe3] + Only small fragments such as these are used, and this is used as the analyte [TeGT] +This allowed for the assignment of energy to the analyte itself. This confirmed that laser energy transfer via heteroatom-modified hydrogen-containing carbon surfaces is relatively soft, without extensive fragmentation of the analyte during desorption. Furthermore, this experiment demonstrated suitability for the derivatization of analytes often used, for example, in the analysis of steroids.

[0158] Furthermore, permanently negative analytes were tested. A solution of sodium dodecyl sulfate (SDS, 100 μg / mL in H2O) was applied to a heteroatom-modified hydrogen-containing carbon surface (1 μL) and dried. Subsequently, SALDI measurements were performed by irradiation at an intensity of 400 units. As shown in Figure 14, a product ion scan at m / z 265.1 (CE=20 eV) was recorded to show the corresponding fragmentation of dodecyl sulfate. Figure 14 shows the product ion scan of the permanently negatively charged analyte dodecyl sulfate (DC) measured on a purified heteroatom-modified hydrogen-containing carbon surface at a laser energy of 400 units in negative ion mode. Dodecyl sulfate anion [DS] - It was observed with very high intensity. The main fragment was [HSO4] - This reaction occurred, indicating the desorption of the sulfate terminal group of dodecyl sulfate. Thus, the desorption of negatively charged analytes on heteroatom-modified hydrogen-containing carbon surfaces was successfully demonstrated.

[0159] Further observations were made regarding the SALDI performance of heteroatom-modified hydrogen-containing carbon surfaces to demonstrate analyte desorption and ionization with accurate isotopic patterns. Eosin Y (EY), a histologically important stain, was selected as a model substrate due to the presence of four bromine atoms in its structure. 1 μL of analyte solution (EY, 1 mg / mL in MeOH / H2O = 80 / 20) was spotted onto the heteroatom-modified hydrogen-containing carbon surface, dried, and subsequently measured by SALDI mass spectrometry (360 units laser intensity) in negative ion mode. The observed full scan showed the deprotonated molecule [EY-H] -The main formation was shown. As shown in Figures 15A and 15B, by expanding the range from m / z 640 to m / z 653, species [C 20 H7Br4O5] - The predicted shape of the isotopic pattern was confirmed. Figures 15A and 15B show the [EY-H] in the range of m / z 640 to m / z 653. - The isotope patterns of (Figure 15A) and [EY-H] - This shows a corresponding magnified view of the calculated ion pattern (Figure 15B). Since isotope-labeled internal standards are a key consideration in commonly used quantitative analyses, this experiment highlights the broad applicability of the heteroatom-modified hydrogen-containing carbon surface described herein.

[0160] Example 3 As a third example, we evaluated the quantitative analysis of analytes on a heteroatom-modified hydrogen-containing carbon surface using SALDI-MS.

[0161] While the qualitative performance and usefulness of heteroatom-modified hydrogen-containing carbon surfaces for SALDI-MS have been detailed above, their quantitative capabilities are even more valuable. For this analysis, targets with heteroatom-modified hydrogen-containing carbon surfaces were used, and two sequential dilutions were performed in positive and negative ion modes, respectively. The results were then compared with those of blank and weathered steel sheets.

[0162] First, as an internal standard 13 A serial dilution of progesterone containing C3Pr was selected. The detailed concentrations of Pr were 10 μg / mL, 1.0 μg / mL, 100 ng / mL, and 10 ng / mL, but all samples were given a concentration of 1.6 μg / mL. 13 C3Pr was added. Each analyte solution was spotted separately on a purified heteroatom-modified hydrogen-containing carbon surface in a sample volume of 1 μL and dried. The following SALDI-MS measurements, in which each spot was irradiated with a laser intensity of 450 units, showed that Pr and 13 C3-Pr's [M+H] + and [M+Na] +Adducts are detected. As can be seen from Figure 16, the combined intensity [Pr+H] of each analyte spot + and [ 13 [C3Pr+H] + Evaluate the combined intensity ratio Pr / 13 C3Pr, CIR Pr / 13 C3Pr was calculated and plotted against the corresponding concentration c. Figure 16 shows the synthetic intensity ratio Pr / for Pr concentrations c in the range of 10 μg / mL to 10 ng / mL. 13 C3Pr CIR Pr / 13 The plot of C3Pr is shown along with a linear regression line, and further expanded over the range from 1.0 μg / mL to 10 ng / mL. A linear dependence was observed across the entire range. Even at 10 ng / mL, progesterone was successfully detected, and considering the low sample volume, this was equivalent to a total of 32 fmol in a single spot. Therefore, heteroatom-modified hydrogen-containing carbon surfaces are applicable to the quantification of progesterone using an internal standard by SALDI mass spectrometry in positive ion mode.

[0163] Quantitative analysis using heteroatom-modified hydrogen-containing carbon surfaces was further investigated in negative ion mode using serial dilutions of estradiol. Detailed Es concentrations were 10 μg / mL, 1.0 μg / mL, 100 ng / mL, and 10 ng / mL. 13 C3Es was added to all samples at a concentration of 1.6 μg / mL as an internal standard. Each analyte solution was spotted separately on a purified heteroatom-modified hydrogen-containing carbon surface with a sample volume of 1 μL and dried. The following SALDI-MS measurements, performed in negative ion mode with a laser intensity of 380 units on each spot, were used to measure Es and 13 About C3Es [MH] - This resulted in the detection of [Es-H]. As can be seen in Figure 17, the combined intensity of each analyte spot [Es-H] - and [ 13 C3Es-H] - Evaluate the combined intensity ratio Es / 13 C3Es CIR Es / 13C3Es was calculated and plotted against the corresponding concentrations. Figure 17 shows the composite intensity ratio Es / for Es concentrations c in the range of 10 μg / mL to 10 ng / mL. 13 C3Es CIR Es / 13 The plot of C3Es is shown along with a linear regression line, and further expanded to cover the range from 1.0 μg / mL to 10 ng / mL. A linear dependence was observed up to a concentration of 100 ng / mL. Considering the low sample volume, this was comparable to a total of 369 fmol in a single spot. Therefore, heteroatom-modified hydrogen-containing carbon surfaces are applicable to the quantification of estradiol using an internal standard by SALDI mass spectrometry in negative ion mode.

[0164] To verify that the desorption and ionization of the analyte are affected by the heteroatom-modified hydrogen-containing carbon surface, serial dilutions of estradiol were measured again on bare and rusted steel plates. A similar weathering effect on stainless steel is mentioned by Reichardt et al., Analyst 2014, 139, 2873, DOI 10.1039 / c4an00216d, and the latter was further selected because it manifests in several SALDI performances. The steel plates were weathered in an aqueous NaCl bath for 1 day and thoroughly washed with deionized water, tetrahydrofuran, and acetonitrile. Estradiol from the previously prepared dilution series was spotted onto both the bare and rusted steel plates at a sample volume of 1 μL and dried. In the following SALDI-MS measurements, each spot was irradiated with a laser intensity of 380 units in negative ion mode, and the [MH] of Es was measured. - Furthermore 13 C3Es was hardly detected. As can be seen in Figure 18, the total count of each analyte spot [Es-H] was significantly higher compared to the results for heteroatom-modified hydrogen-containing carbon surfaces. - The [Es-H] ratio was evaluated and plotted against the corresponding concentration. Figure 18 shows the [Es-H] ratio against the concentration of Es in the range of 10 μg / mL to 10 ng / mL on a heteroatom-modified hydrogen-containing carbon surface (1, rectangle) compared with bare steel plate (2, circle) and rusted steel plate (3, triangle). -The plot shows the total count N. Only the bare steel plate yielded a single spot (1.0 μg / mL) in some detection of estradiol, which appeared to be a more outlier as there was no further detection of the analyte at all other concentrations. Furthermore, the rusted steel plate yielded no detection of the analyte, even at the highest concentration of estradiol of 10 μg / mL. In contrast, the heteroatom-modified hydrogen-containing carbon surface yielded significant desorption and ionization of the estradiol serial dilution samples. These experiments demonstrated that the desorption and ionization of the analyte is initiated by the heteroatom-modified hydrogen-containing carbon surface itself during laser irradiation, while the plain steel plate and rusted steel plate lack the ability to effectively desorb and ionize the analyte, particularly quantitatively.

[0165] Example 4 As a fourth example, the reusability of a heteroatom-modified hydrogen-containing carbon surface was evaluated.

[0166] Another beneficial feature of the SALDI surface coating is its reusability, which does not significantly reduce its functional efficiency. Since there were no visible signs of degradation of the heteroatom-modified hydrogen-containing carbon surface after measurements with up to 450 units of laser irradiation, additional experiments were conducted to estimate the reusability of the heteroatom-modified hydrogen-containing carbon surface. For this purpose, a new target with a heteroatom-modified hydrogen-containing carbon surface was cleaned and both were treated with Pr and at a concentration of 1.0 μg / mL. 13 The analyte solution consisting of C3Pr was spotted in a double-barreled manner, dried, and measured by SALDI-MS at a laser intensity of 450 units. The target, which had a heteroatom-modified hydrogen-containing carbon surface, was washed again, and this procedure was repeated four more times. The normalized composite intensity ratio Pr / 13 C3Pr NCIR Pr / 13 C3Pr to [M+H] + and [M+Na] + Calculate for both and the number of times the position was used N tThe plot was obtained against [Pr+Na]. An example of the relevant portion of the first full scan mass spectrum is shown in Figure 19A, and a plot of the combined intensity ratio is shown in Figure 19B. Figure 19A is obtained from the first SALDI-MS measurement on a heteroatom-modified hydrogen-containing carbon surface with a laser intensity of 450 units [Pr+Na] + and [ 13 [C3Pr+Na] + Figure 19B shows the respective parts (m / z 330 to m / z 348) of the full scan mass spectrum, and the number of times the position was used N t [M+H] plotted against N=2(2, circle) + (1, Triangle) and [M+Na] + Normalized composite intensity ratio Pr / 13 C3Pr NCIR Pr / 13 This shows C3Pr. We can conclude that even when the same spot is used five times and the laser intensity is increased, there is no significant loss of laser desorption and ionization performance on heteroatom-modified hydrogen-containing carbon surfaces.

[0167] Example 5 As a fifth example, we evaluated the performance in the presence of realistic matrices.

[0168] In relation to the broad analyte range, quantification, and reusability opportunities of heteroatom-modified hydrogen-containing carbon surfaces in SALDI mass spectrometry, a final investigation was conducted to elucidate their performance in the presence of realistic matrices such as tissues, serums, and whole cell samples. The successful application of heteroatom-modified hydrogen-containing carbon surfaces in the analysis of diverse biological or diagnostic samples represents a major leap forward in the cutting edge of SALDI mass spectrometry technology.

[0169] The first experiment aimed to demonstrate the desorption and ionization of selected analytes in the presence of treated formalin-fixed paraffin-embedded (FFPE) tonsil tissue samples. The paraffin of the FFPE tissue sample was carefully heated to 36°C to soften and washed off with a small amount of tetrahydrofuran. The tonsil tissue sample was macerated with a few drops of deionized water and transferred to a heteroatom-modified hydrogen-containing carbon surface of the target. 1 μL of 10 μg / mL estradiol sample solution was added to a defined spot on the tissue sample. The following SALDI measurements in negative ion mode were performed at a laser intensity of 380 units, with one mass spectrum recording the background of the treated FFPE tonsil sample and the other mass spectrum recording the spot with estradiol spiked at the top. Both mass spectra can be compared in Figures 20A and 20B. Figures 20A and 20B show full-scan SALDI mass spectra of a treated FFPE tonsil tissue sample on a heteroatom-modified hydrogen-containing carbon surface with tissue background (Figure 20A) and estradiol-doped tissue operating in negative ion mode with a laser intensity of 380 units (Figure 20B). The background of the tissue sample itself and residual paraffin was clearly visible in the corresponding mass spectra. Despite the background signal, the spot on the previously estradiol-doped sample was [Es-H] - This clearly demonstrated the detection of [specific element]. This is a very important result because it reveals that the SALDI performance of heteroatom-modified hydrogen-containing carbon surfaces is not limited to sample solutions but is also useful for the analysis of tissue samples with challenging matrices.

[0170] Successful SALDI analysis of heteroatom-modified hydrogen-containing carbon surfaces in the presence of complex matrices has also led to the consideration of using this surface coating for SALDI imaging mass spectrometry. In tissue samples thin enough to allow laser pulses to pass through the a-C:H:Si:X layer, direct energy transfer from the coating to the tissue might be possible. This could eliminate extensive sample preparation by matrix application and provide high spatial resolution. For this experimental observation, thin slices of garlic cloves (Allium sativum obtained from a local grocery store) were used as model substrates. The cross-sections contained buds surrounded by storage leaves and simply pressed onto the a-C:H:Si:X layer. SALDI imaging was performed in positive ion mode with a laser energy of 380 units, a laser repetition frequency of 2.5 kHz, and a spatial resolution of 50 μm × 50 μm. The resulting mass spectra showed several detected low- to medium-molecular weight compounds. Some substances could be assigned. In particular, glycans of different chain lengths were recognized mainly as potassium ions [M+K] + but some potential natural products could also be seen. In Figure [21A], an image of the spatial distribution of sucrose [M+K] + is shown, while in Figure [21B], the spatial distribution of m / z 527.1 is shown. The intensity of the detected signal corresponds to a relative scale with an increase in tone. Thus, a white or bright background corresponds to a low relative distribution from the absence of the corresponding compound, and a black or dark pixel color corresponds to a high relative detection distribution of the corresponding compound. Specifically, Figure [21A] shows the spatial distribution of m / z 381.1 assigned to sucrose [M+K] + as a result of the SALDI imaging experiment of the garlic clove cross-section on a heteroatom-modified hydrogen-containing carbon surface, and Figure [B] shows probably draconin [M+K] +This shows the spatial distribution of m / z 527.1 assigned to this value. This experiment demonstrates the potential of heteroatom-modified hydrogen-containing carbon surfaces, even in their use as targets for SALDI imaging mass spectrometry of biological or analytical samples. [Explanation of Symbols]

[0171] 110 Targets 112 Surface 114 layers 116 Heteratom-modified hydrogen-containing carbon layer 118 circuit boards 120 Laser Desorption Mass Spectrometer 122 lasers 124 Mass Spectrometry Unit 126 Chamber 128 Vacuum pump 130 Arrow 132 pulsed laser 134 Arrow 136 Mass Separation Module 138 Readout Electronic Circuits 140 Continuous Desorption / Desorption Mass Spectrometer System 142 Material Strips 144 rolls 146 Surface 148 stations 150 Liquid Processing Systems 152 Vacuum Systems 154 Pipetting Unit 156 areas 158 Vacuum Zone 160 First Vacuum Zone 162 The second vacuum zone 164 stacks 166 Platelet 168 samples 170 Platelet Holder 172 Surface 174 layers 176 Conductive contact layer 178 Surface 180 Middle Class 182 Outermost layer

Claims

1. A target (110) for use in a laser desorption mass spectrometer, wherein the target (110) has at least one surface (112), the surface (112) is at least partially covered by at least one layer (114), the layer (114) being a hydrogen-containing silicon-integrated amorphous carbon (a-C:H:Si) layer (116), the a-C:H:Si layer (116) is ● 40 atomic percent to 80 atomic percent carbon, ● 1 atomic percent to 20 atomic percent of hydrogen, ● 10 to 40 atomic percent silicon Target (110), including the target.

2. The a-C:H:Si layer (116) is a hydrogen-containing, heteroatom-modified, silicon-integrated amorphous carbon (a-C:H:Si:X) layer, wherein the heteroatom X is selected from the group consisting of oxygen, nitrogen, fluorine, and boron, and the a-C:H:Si:X layer is ● Up to 15 atomic percent of oxygen, ● Up to 10 atomic percent of nitrogen, ● Up to 10 atomic percent of boron, and ● Up to 5 atomic percent of fluorine It further includes, The target (110) according to claim 1, wherein the total amount of oxygen, nitrogen, fluorine, and boron is at least 1 atomic percent.

3. The target (110) according to claim 1, wherein the a-C:H:Si layer (116) is deposited on the surface (112) of the target (110) by a plasma-assisted surface coating process.

4. The target (110) according to claim 1, wherein the target (110) comprises at least one substrate (118), the substrate (118) being made of at least one material selected from the group consisting of glass; steel, stainless steel; aluminum; silicon; germanium; titanium; copper; cobalt; chromium; molybdenum; nickel; tungsten; tantalum; graphite; polymer materials, polyethylene, polypropylene, polycarbonate, polystyrene, polyacrylate, polyaniline, poly(3,4-ethylenedioxythiophene)polystyrene sulfonate, polypyrrole, and polythiophene.

5. A laser desorption mass spectrometer (120), a) A target (110) according to at least one of claims 1 to 4, b) at least one laser (122), wherein the laser (122) is configured to supply energy to the target (110) such that at least one ion of at least one analyte is generated, c) At least one of a mass spectrometry unit (124) and an ion mobility spectrometer A laser desorption mass spectrometer (120) is provided.

6. A continuous laser desorption mass spectrometer system (140) comprising at least one laser desorption mass spectrometer (120) according to claim 5, wherein the target (110) is provided as a stack (164) of material strips (142) or platelets (166).

7. The continuous laser desorption mass spectrometer system (140) according to claim 6, wherein the continuous laser desorption mass spectrometer system (140) further comprises at least one vacuum system (152), and the continuous laser desorption mass spectrometer system (140) is configured to pass the material strip (142) or the platelet (166) through the vacuum system (152).

8. A kit comprising (i) a target (110) according to at least one of claims 1 to 4, and (ii) at least one internal standard.

9. Use of the target (110) according to any one of claims 1 to 4 for laser desorption mass spectrometry detection of at least one analyte in a sample (168).

10. The use according to claim 9, wherein the analyte is selected from the group consisting of steroids, ketosteroids, secosteroids; therapeutic agents; detergents; glycosides; peptides; proteins; dyes; ions; nucleic acids; amino acids; metabolites; hormones; fatty acids; lipids; and carbohydrates.

11. The use according to claim 9, wherein the analyte has a molar mass of 6 Da to 10,000 Da or 6 Da to 3,000 Da.

12. The use according to claim 9, wherein the analyte comprises permanently positively charged molecules or permanently negatively charged molecules.

13. The use according to claim 9, wherein the analyte is provided in a sample, and the sample is selected from the group consisting of physiological fluids including blood, serum, plasma, saliva, lens fluid, cerebrospinal fluid, sweat, urine, lactation, ascites fluid, mucus, synovial fluid, peritoneal fluid, amniotic fluid, tissue, or cells.

14. A method for preparing at least one sample (168) for analysis in a laser desorption mass spectrometer (120), i. To provide a target (110) according to at least one of claims 1 to 4, ii. Applying at least one sample (168) to the target (110), wherein the sample (168) contains at least one analyte. Methods that include...

15. A method for detecting at least one analyte in a sample (168) using a laser desorption mass spectrometer (120), I. A method for preparing at least one sample (168) for analysis in a laser desorption mass spectrometer (120) according to claim 14. To perform, II. To detect the at least one analyte in the sample (168) using the laser desorption mass spectrometer (120) according to at least one claim 5. Methods that include...

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