306 results about "Ionization mass spectrometry" patented technology

A sample preparation method is disclosed for volatilization and mass spectrometric analysis of nonvolatile high molecular weight molecules. Photoabsorbing molecules having significant sublimation rates at room temperature under vacuum, and preferably containing hydroxy functionalities, are disclosed for use as matrices in matrix-assisted laser desorption / ionization mass spectrometry. The samples are typically cooled in the mass spectrometer to temperatures significantly below room temperature.

A method and apparatus are provided for identifying analytes at low concentrations in a liquid sample. The liquid sample is introduced through a continuous flow membrane inlet system. The analytes that permeate the membrane are analyzed by photoionization-time-of-flight mass spectrometry. The analytes remaining in the liquid sample that do not permeate the membrane are conducted to a capillary tube inlet that introduces the liquid sample and other analytes as droplets into the photoionization zone. Any analytes remaining absorbed or adsorbed on the membrane are driven through the membrane by application of heat. Analytes may be analyzed by either resonance enhanced multiphoton ionization (REMPI) or single photon ionization (SPI), both of which are provided in the apparatus and can be selected as alternative sources.

The present invention provides a mass spectrometer having an ion lens capable of transporting an ion having a large mass to charge ratio with a high level of ion-passing efficiency even under a low-vacuum atmosphere. In conventional atmospheric pressure ionization mass spectrometers or similar mass spectrometers, applying an excessively high voltage to the ion lens undesirably causes an electric discharge. Therefore, the passing efficiency for an ion having a large mass to charge ratio cannot be adequately improved, which leads to a poor detection sensitivity. To solve this problem, the mass spectrometer according to the present invention includes a voltage controller 21 that controls a variable radiofrequency (RF) voltage generator 24 so that both the amplitude and the frequency of the RF voltage applied to the lens electrodes of an ion lens 5 are changed according to the mass to charge ratio of an ion to be analyzed. This control enables the ion lens 5 to focus an ion and transport it to the subsequent stage with a high level of passing efficiency even in the case of analyzing an ion having a large mass to charge ratio. Thus, the detection sensitivity is improved. The aforementioned control is conducted on the basis of the control data stored in a voltage control data storage 22. These data are obtained in advance by a measurement of a sample containing a substance having a known mass to charge ratio, in which the intensity of the signal of an ion detector is maintained while the analysis conditions are changed.

The present invention provides a device, system, and associated methods to actively or passively sample air by directing it onto the surface of a porous light-absorbing semiconductor, for example, a desorption / ionization on porous silicon (“DIOS”) chip. Upon adsorption of an analyte, the surface may be analyzed directly by laser desorption / ionization time-of-flight mass spectrometry. Because the process of laser desorption / ionization and subsequent mass detection does not require elevated temperatures, thermal degradation of analytes is avoided.

Mesoporous silica is shown to be a sample holder for laser desorption / ionization of mass spectrometry. Supported mesoporous silica was prepared by coating an ethanolic silicate solution having a removable surfactant onto a substrate to produce a self-assembled, ordered, nanocomposite silica thin film. The surfactant was chosen to provide a desired pore size between about 1 nanometer diameter and 50 nanometers diameter. Removal of the surfactant resulted in a mesoporous silica thin film on the substrate. Samples having a molecular weight below 1000, such as C60 and tryptophan, were adsorbed onto and into the mesoporous silica thin film sample holder and analyzed using laser desorption / ionization mass spectrometry.

The present invention provides methods for obtaining information of a plurality of target molecules by matrix free LDI MS. Mass tagged complexes for detection of target molecules comprise a target molecule binding domain, and a mass tag separated by a cleavable linker. Methods of the invention may be used for example to analyze the distribution of a multiple target molecules in a complex sample, such as a tissue section.

A method of enhanced speciation of both positive and negatives species in an analyte is disclosed. The method can include producing a first analyte solution comprising an analyte composition and an effective amount of silver triflate, and analyzing the first analyte solution with an electrospray ionization mass spectrometer. The method can also include producing a second analyte solution comprising a portion of the analyte composition and an effective amount of a compound of formula I, and analyzing the second analyte solution with an electrospray ionization mass spectrometer. The compound of formula I is [NX+][OH−], where X is a linear, branched, or cyclic C1-C10 alkane; an aryl; a heterocyclic aromatic; or a heterocyclic moiety.

The present invention relates to a probe for the analysis of one or more analytes, particularly proteins or compounds capable of binding or otherwise interacting therewith, by laser desorption / ionization mass spectrometry, more particularly MALDI MS. It also relates to a protein microarray, a method of producing a protein microarray and a method of analyzing a protein microarray. The probe comprises a support having an electroconductive target surface thereon characterized in that the target surface comprises a micro array having a plurality of discrete target areas presenting one or more analyte capture moieties. Each discrete target area has an area of less than 1000 μm2, more preferably still less than 500 μm2, and more preferably still less than 100 μm2.

The invention relates to a novel electro-spray sampling vacuum ultraviolet single-photon ionization mass spectrometry analysis device which solves the analysis problems of a plurality of non-polarity composition complex systems. The device of the invention comprises a photoionization chamber and a differential chamber which are adjacent to each other; the adjacent side walls of the photoionization chamber and the differential chamber are communicated with a perforated ladle which is convex towards the differential chamber; the outlet of the perforated ladle is corresponding to the middle of the lead-out electrode and acceleration electrode of a time-of-flight mass spectrometer; the inlet of the perforated ladle is corresponding to an inverted horn-shaped nozzle on the side wall of the differential chamber; the inlet of the perforated ladle is in inverted horn shape; an electro-spray needle corresponding to the nozzle is arranged outside the differential chamber; the other end of the electro-spray needle is connected with an injection pump. The device of the invention combines the electro-spray sampling and vacuum ultraviolet photoionization mass spectrometry technique, directly sprays the sample to be measured out of the electro-spray needle during the testing and analysis process, and requires no complex pre-processing and separation of the sample; as the electro-spraying has no restrictions on the thermal stability and volatility of the sample, the device of the invention can be widely applied to the analysis and detection of simple organic matters and complex organic mixtures and can monitor certain organic reaction processes in real time.

A method and apparatus for conducting mass spectrometry. The mass spectrometry may be accomplished by ion drift-chemical ionization mass spectrometry. One embodiment includes a chemical ionization mass spectrometer comprising an ion drift zone having an ion conductor that transports positive or negative ions. The chemical ionization mass spectrometer further comprises an ion source that produces the positive or negative ions and a mass spectrometer.

The invention relates to a novel IR laser desorption / vacuum UV single-photon ionization mass spectrum analyzing device for analysis and detection of a biological sample, which solves the problems of the prior art that uses matrix and is unlikely to analyze complex mixture with low polarity and low molecular weight. The device is structurally characterized in that a photoionization chamber is arranged on one side of a time-of-flight mass spectrometer, an ion injection hole is provided on one sidewall of the photoionization chamber, an ion injector and a sample target are arranged in the chamber, a laser is disposed outside the photoionization chamber on the sample target side, and vacuum UV light source is arranged on the other side. By combining IR laser desorption technology and vacuum UV ionization mass spectrum technology, the invention can achieve high-efficiency and rapid analysis without selecting different matrixes according to the sample and without complex pre-treatment and separation of the sample, thus preventing the matrix interference on mass spectral signals. The invention is specifically suitable for analysis of thermal-unstable and nonvolatile organic compounds and biological molecules.

A method for directly analyzing a lung cancer tissue sample based on the tissue electro-spray ionization mass spectrometry concretely comprises the steps that an electro-spray extraction ionization source in the tissue sample is set up; an extraction agent, namely, methyl alcohol is sucked through a micro-syringe connected with a quartz capillary, the extraction agent is dripped on the surface of the sample through the quartz capillary, and an injection pump controls the micro-syringe; the lung cancer tissue sample is cut into a piece of which the volume is 1 mm3 and placed at the tip of an acupuncture needle, and the needle tip is inserted into the sample and keep unexposed; the distance between the front end of the sample and an inlet of a mass spectrometer is adjusted, and the tail end of the acupuncture needle, the front end of the sample and the inlet of the mass spectrometer are adjusted to be in a horizontal coaxial state; DC voltage is applied on the acupuncture needle, so that extraction, desorption and ionization happen on the sample, and the sample generates spray which enters the mass spectrometer. According to the method, the information of molecules in the sample can be directly and quickly obtained, and the result shows that the method is a mass spectrometry method which has the advantages that the device is simple, manufacturing cost is low, ionization efficiency is high, and damage to the sample is small.

The invention discloses a capillary needle. The capillary needle comprises a tube body, the two ends of the tube body are respectively provided with an inlet and an outlet for electro-spray, a part of the tube body is bent to form a sampling end, and the sampling end is provided with a sampling port communicating with a cavity in the tube body. The invention also discloses an electro-spray ionization mass spectrometry analytical apparatus applying the capillary needle. The invention also simultaneously discloses a method applying the electro-spray ionization mass spectrometry analytical apparatus for analytical detection. The analytical apparatus is high in integration, compact in structure, easy to control, small in size and low in cost; the sample consumption is greatly reduced, and the experiment cost is decreased; an integrated sample introduction method is employed, and an sample introduction end does not have to be repeatedly placed in a sample and blank solution, such that cross contamination is reduced, and more importantly, the analytical flux is substantially improved; and through combination with an automatic sample changing system, different samples can be automatically introduced, and therefore, the capillary needle, the apparatus and the method are quite suitable for such fields as high-flux screening, unicell analysis, mass spectrum imaging analysis and the like.

A set of electrodes to which different potentials are applied at different time periods to perform ion mobility-based spectroscopy and mass spectrometry (MS) on an ion sample by performing any number of ion mobility-based Spectroscopy and mass spectrometry to process ions and are performed as separate or overlapping steps to capture, separate and analyze charged particles and charged particles originating from atoms, molecules, particles, subatomic particles and ions.

A method for determination of at least one of the lipid species in a biological sample comprising subjecting the sample to lipid extraction to obtain a lipid extract and subjecting the resulting lipid extract to multidimensional electrospray ionization mass spectrometry using either precursor ion or neutral loss scanning (or both) of all naturally occurring aliphatic chains, lipid fragments and precursor ions leading to observed fragments to generate a multidimensional matrix whose contour densities provides structural and quantitative information directly without chromatography. A method for determination of lipid content and / or lipid molecular species composition and quantity directly from lipid extracts of a biological sample comprising subjecting said lipid extract to electrospray ionization multidimensional mass spectrometry by comparisons to standards and algorithms described herein.

Prior work on differential mobility analysis (DMA) combined with mass spectrometry (MS) has shown how to couple the output of the DMA with the inlet of an atmospheric pressure ionization mass spectrometer (APCI-MS). However, the conventional ion inlet to an APCI-MS is a round orifice, while conventional DMA geometries make use of elongated slits. The coupling of two systems with such different symmetries limits considerably the resolutions attainable by the DMA in a DMA-MS combination below the value of the DMA alone. The purpose of this invention is to overcome this limitation in the case of a parallel plate DMA. One solution involves use of an elongated rather than a circular MS sampling hole, with the long dimension of the MS inlet hole aligned with that of the DMA slit. Another involves use of a more elongated orifice in the DMA exit and a more circular hole on the MS inlet, the two being connected either through a short transfer conduit or through an ion guide. The DMAs described can also be coupled profitably to detectors and analyzers other than mass spectrometers.

The ionization chamber consists of a plurality of ports to accept multiple identical devices or varying devices. Ports may be arranged at various positions on the ionization chamber and at various angles with respect to the sampling orifice leading into the vacuum chamber of the mass spectrometer. A plurality of sprayers may operate in a time modulated manner and thereby the simultaneous multiplexed analysis of a multitude of samples is facilitated.

Laser desorption / ionization time-of-flight mass spectrometer (“LDI-TOF-MS”) devices, and methods, that accurately measure the mass of analytes contained in a sample and which also measure the quantities of analytes present in a sample in a consistent manner from instrument-to-instrument and over time on a single instrument. In particular, the invention provides LDI-TOF-MS devices and methods in which: 1) the energy of the laser pulse and the area of the sample illuminated (fluence) is consistent and controlled so as to produce consistent conditions for analyte desorption and ionization; 2) the mass analyzer behaves in a reproducible manner; and 3) the detection system produces a signal that consistently represents the arrival of ions of different masses.

There is disclosed an apparatus for providing an ionized analyte for mass analysis by photon desorption comprising at least one layer for contacting an analyte, and a substrate on which said layer is deposited. Upon irradiation of said apparatus, said analyte desorbs and ionizes for analysis by mass spectrometry. The layer or layers of said apparatus comprise a continuous film, a discontinuous film or any combinations thereof.

The invention provides a simple, rapid and cost-effective metal oxide-assisted laser desorption / ionization mass spectrometry (MOALDI MS) without the addition of light-absorbing organic-matrix, comprising the use of (a) an inorganic metal oxide with light absorbing capability as an assisting material to render desorption / ionization of samples in laser desorption / ionization mass spectrometry and (b) a citric acid buffer as the proton source for enhancing the ionization efficiency for analytes. Metal oxide assisting materials is not only restricted to the uses of films. Metal oxide nanoparticles are also suitable to be used as the assisting materials. Low matrix background, stable surface feature, homogeneous sample deposition, and wide detectable mass range are the merits of MOALDI MS.

The utility model relates to a normal pressure chemical extraction ionization source, equipped with an ionization pipe and a sample pipe. The ionization pipe and the sample pipe are aslant arranged within an included angle and a distance, and the ports of the ionization pipe and the sample pipe point an ionization area jointly. The sample pipe comprises a sample inlet pipe and a sample carrying gas pipe, a gas or liquid sample is guided in the sample inlet pipe or the sample inlet pipe is communicated with a sample eduction pipe of a neutral desorbing device. The method of utilizing the normal pressure chemical extraction ionization source of the utility model comprises the steps of using a sample flow educed from the sample pipe and an ion flow educed from the ionization pipe to impact with each other to occur the extraction ionization, and then carrying out a mass spectrometry. The normal pressure chemical extraction ionization source is especially suitable for the real-time rapid analysis of complicated samples, such as biological sample, food, drugs, environmental sample, etc.

The invention belongs to the technical field of analysis and in particular relates to a device and method for combining electrochemistry with electrospray ionization mass spectrometry. The device is composed of an electrochemical reactor and an electrospray ionization ion source. The electrochemical reactor comprises a work electrode chamber and an auxiliary electrode chamber which are isolated from each other through a diaphragm, the diaphragm has the effects of preventing or delaying a neutral substance from exchanging between the electrode chambers and allowing an ion to exchange with an electric ion. A solution sample can be subjected to electromechanical reaction under the effect of an electrochemical voltage loaded between the work electrode and the auxiliary electrode when flowing in the work electrode chamber. An electrochemically reacted product is protected by the diaphragm and then forms an air-phase ion under the effect of the electrospray ionization work voltage, and the air-phase ion is analyzed by a mass spectrometer. According to the invention, the electromechanical reaction efficiency is higher, the electromechanically reacted product is simple, and the response speed is high, thus the device and method provided by the invention adapt to the rapid, accurate and high-flexible advantages of the quantitative analysis and the mass spectrum analysis.

The invention relates to a method for distinguishing true apple juice from false apple juice by virtue of liquid chromatogram- isotope ratio mass spectrometry (LC-IRMS) determination. The method can be used for effectively distinguishing true apple juice from false apple juice and ensuring the quality safety of apple juice products. The method comprises the following steps: respectively preparing apples from different places into apple juice samples; analyzing plant polysaccharides in the prepared apple juice samples to establish plant polysaccharide determination conditions, and analyzing malic acid in the apple juice to establish the plant polysaccharide determination conditions; and analyzing natural apple juice to establish a linear relationship between the delta <13>C ratio of plant polysaccharides and malic acid in the apple juice to make judgment on the true and false apple juice, wherein if the delta <13>Csuc (sucrose) ranges from -1.909% to -2.647%, the delta <13>Cglu (glucose) ranges from -2.452% to -3.050%, the delta <13>Cfru (fructose) ranges from 2.522% to 3.196%, the ratio delta 1 of plant polysaccharides ranges from 0.27 to 2.78, the delta <13>Cmal (malic acid) ranges from -2.531% to 3.257% and the linear dependence coefficient R2 is more than 0.7255, the apple juice is true. The method is accurate in determination results and high in sensitivity, the quality of apple juice can be effectively guaranteed, adulterated apple juice can be prevented from causing injury to consumers, and economic and social benefits are tremendous.

The invention discloses a chemical ionization mass spectrometer for selectively controlling reaction ions, which comprises an ion source, a reaction ion selecting cavity, a chemical ionization reaction cavity and a mass spectrum detecting cavity, wherein the ion source is used for generating mixed ions; a certain ion in the mixed ions can selectively pass through the reaction ion selecting cavity; two parallel-plate electrodes are arranged in the reaction ion selecting cavity; and the parallel-plate electrodes are connected with a controllable radio-frequency power supply. According to the chemical ionization mass spectrometer provided by the invention, the mixed ions are separated by controlling radio-frequency voltage alternating current components loaded on the parallel-plate electrodes and a direct current component is utilized to select one ion, so as to realize the selective control on the passing of any ion; the ion enters the chemical ionization reaction cavity and is served as the reaction ion for chemical ionization, so as to realize the ionization on a to-be-detected object and detect in the mass spectrum detecting cavity; the chemical ionization mass spectrometer provided by the invention can work under atmosphere pressure and has the characteristics of simplicity in technology and low cost; various reaction ions are selectively controlled and the scope of materials detected by the chemical ionization mass spectrometer is expanded; and the identifying analytical capability of an instrument on unknown samples is increased.

The present invention is a method to determine the TAN and TAN as a function of boiling point for a hydrocarbon feedstream using an electrospray ionization mass spectrometer (ESI-MS). The steps of the method include determining the signal as a function of mass from the ESI-MS while minimizing the formation of oligomers and fragmentation of the molecular species in the feedstream and then determining the TAN from the signals. The TAN is also determined as a function of boiling point.

A method for diagnosing Amyotrophic lateral sclerosis includes providing surface-enhanced laser desorption / ionisation mass spectrometric (SELDI-MS) data of a plurality of proteins, said data obtained from a patient and comprising a plurality of peak values, and analysing said peak values with an alternating decision tree comprising a set of tests of said data peaks values and associated prediction values, wherein said data is predictive of depression if a sum of the prediction values of said tree is greater than 1.0.

Prior work on differential mobility analysis (DMA) combined with mass spectrometry (MS) has shown how to couple the output of a planar DMA with the atmospheric pressure inlet of an atmospheric pressure ionization mass spectrometer (APCI-MS). However, because the ion inlet to APCI-MS instruments is a round orifice, while conventional DMA geometries make use of elongated slits, the coupling of both has attained less resolving power or tolerated a smaller sample flow rate than a DMA alone. The present invention overcomes these limitations with an axial DMA of cylindrical symmetry using more than two electrodes. The configuration is related to that previously proposed by Labowsky and Fernández de la. Mora (2004, 2006), where ions with a critical electrical mobility are brought into the symmetry axis of the DMA. Ions with this critical mobility are now optimally transmitted into the MS, with much higher resolution than possible in planar DMAs. In a preferred embodiment of this DMA facilitating DMA-MS coupling, one DMA electrode intersecting the symmetry axis is relatively planar.

A method and apparatus for probing the chemistry of a single droplet are provided. The technique uses a variation of the field-induced droplet ionization (FIDI) method, in which isolated droplets undergo heterogeneous reactions between solution phase analytes and gas-phase species. Following a specified reaction time, the application of a high electric field induces FIDI in the droplet, generating fine jets of highly charged progeny droplets that can then be characterized. Sampling over a range of delay times following exposure of the droplet to gas phase reactants, the spectra yield the temporal variation of reactant and product concentrations. Following the initial mass spectrometry studies, we developed an experiment to explore the parameter space associated with FIDI in an attempt to better understand and control the technique. In an alternative embodiment of the invention switched electric fields are integrated with the technique to allow for time-resolved studies of the droplet distortion, jetting, and charged progeny droplet formation associated with FIDI.