557 results about "ESI mass spectrometry" patented technology

This invention provides methods, devices and device components for preparing ions from liquid samples containing chemical species and methods and devices for analyzing chemical species in liquid samples. The present invention provides an ion source for generating analyte ions having a selected charge state distribution, such as a reduced charged state distribution, that may be effectively interfaced with a variety of charged particle analyzers, including virtually any type of mass spectrometer.

Charged droplet spray is formed from a solution with all or a portion of the charged droplet spray current generated from reduction or oxidation (redox) reactions occurring on surfaces removed from the first or sample solution flow path. In one embodiment of the invention, two solution flow channels are separated by a semipermeable membrane. A first or sample solution flowing through the first solution flow channel exchanges cation or anion charged species through the semipermeable membrane with a second solution or gas flowing through the second flow channel. Charge exchange is driven by the electric field applied at the charged droplet sprayer sample solution outlet. Redox reactions occur at an electrode surface in contact with the second solution. The invention increases the control and range of the Electrospray ionization process during ES / MS operation. Alternative embodiments of the invention provide for conducting redox reactions on conductive surfaces removed from the first or sample solution flow path but not separated by semipermeable membranes.

This invention describes an apparatus for the separation and collection of components in a sample of interest comprising: an ionization source; an ion mobility separator and an ion collector positioned to receive ions leaving the ion mobility separator. The ion mobility separator having an inlet to supply at least one separating substance which comprises particles which selectively interact with at least one analyte component of interest to certain degree different from the others. The analyte component of interest may be enantiomers, diastereomers, stereoisomers, isomers, etc. The ion collector can be used to conduct analytical, preparative, and semi-preparative separation. In addition, a combined primary electrospray and secondary electrospray ionization source is disclosed to enhance ionization efficiency of interest.

A means and method are disclosed for multiplexing a plurality of samples from multiple sprayer devices to be efficiently transferred to a mass analyzer for subsequent analysis. Sample sprays are formed from a plurality of sprayers, which are desolvated to form the sample ions. The sample ions are then selected from one of the sprayers for transportation into a mass analyzer. To accomplish this, the apparatus of the invention comprises a multi-part capillary wherein a first section thereof is connected to a motor which is able to move this first section from one sprayer to the next. This first section may be a flexible tube-like structure loosely mounted in an aperture of a cone-shaped end of a motor which rotates such that the sampling orifice may be aligned with different sprayers at different times to sequentially and repetitively sample ions produced by each of the plurality of sprayers.

A microfluidic chip formed with multiple fluid channels terminating at a tapered electrospray ionization tip for mass spectrometric analysis. The fluid channels may be formed onto a channel plate that are in fluid communication with corresponding reservoirs. The electrospray tip can be formed along a defined distal portion of the channel plate that can include a single or multiple tapered surfaces. The fluid channels may terminate at an open-tip region of the electrospray tip. A covering plate may substantially enclose most portions of the fluid channels formed on the channel plate except for the open-tip region. Another aspect of the invention provides methods for conducting mass spectrometric analysis of multiple samples flowing through individual fluid channels in a single microfluidic chip that is formed with a tapered electrospray tip having an open-tip region.

A ion source for a mass spectrometer comprises: a capillary having a nozzle for emitting a nebulized fluid sample; an electrode of the capillary; a high voltage power supply; a second electrode disposed within or configurable to be disposed within a path of the nebulized fluid sample; and at least one switch for selecting application of an electrical potential provided by the high voltage power supply to either or both of the capillary electrode or the second electrode, wherein the capillary and capillary electrode are configurable so as to ionize the nebulized fluid sample by electrospray ionization and the second electrode is configurable so as to ionize the nebulized sample by atmospheric pressure chemical ionization.

An ion source able to ionize both liquid and gaseous effluents from interfaced liquid or gaseous separation techniques. The liquid effluents are ionized by electrospray ionization, photoionization or atmospheric pressure chemical ionization and the gaseous effluents from sources such as a gas chromatograph are ionized by a corona or Townsend electrical discharge or photoionization. The source has the ability to ionize compounds from both liquid and gaseous sources, which facilitates ionization of volatile compounds separated by gas chromatography, low volatility compounds separated by liquid chromatography, as well as highly non-volatile compounds infused by electrospray or separated by liquid chromatography or capillary electrophoresis.

An automated electrospray ionization (ESI) device and related methods to optimize electrospray interface conditions for mass spectrometric analysis. The optimization process can be performed with calibration or optimization solutions that produce expected ESI parameters such as an ESI signal or an ion current. The ESI device may include an input / output (I / O) controller that is coupled to an electrospray assembly including an XYZ stage for positioning an electrospray emitter relative to a mass spectrometer orifice. The I / O controller may be connected to a power supply for applying an adjustable electrospray ionization voltage, and an adjustable flow regulator that alters the flow of solution by modifying applied voltage and / or pressure. A central processing unit instructs the I / O controller to control selectively the electrospray assembly based on the resultant signals from the mass spectrometer or the ion currents within the mass spectrometer in accordance with a predetermined optimization algorithm. The resulting ESI signal or ion currents are monitored and provide feedback to the I / O controller which can automatically instruct selected system components to make adjustments as needed to attain optimal settings that produce expected ESI signals or ion currents in the mass spectrometer for selected solutions.

A means and method are disclosed for multiplexing a plurality of samples from multiple sprayer devices to be efficiently transferred to a mass analyzer for subsequent analysis. Sample sprays are formed from a plurality of sprayers, which are desolvated to form the sample ions. The sample ions are then selected from one of the sprayers for transportation into a mass analyzer. To accomplish this, the apparatus of the invention comprises a multi-part capillary wherein a first section thereof is connected to a motor which is able to move this first section from one sprayer to the next. This first section may be a flexible tube-like structure loosely mounted in an aperture of a cone-shaped end of a motor which rotates such that the sampling orifice may be aligned with different sprayers at different times to sequentially and repetitively sample ions produced by each of the plurality of sprayers.

Microfluidic devices provide substances to a mass spectrometer. The microfluidic devices include a substrate having at least one microchannel, a cover arranged on a surface of the microchannel, and at least one electrical potential source. Some embodiments include a microchannel widened at an outlet. Other embodiments position the electrical potential source along a surface of the cover. Still other embodiments include a well in which an electrode and a membrane are disposed. The various embodiments provide stable electrospray ionization of substances from a microfluidic device to a mass spectrometer.

The present invention relates to a spray needle for use in electrospray ionization (ESI) for mass spectrometry. A spray needle is disclosed which is constructed to have an opening along its length such that a sample solution may be more readily introduced or loaded therein. Further, the design of the spray needle of the invention is more durable than the prior art spray needles and may be reusable. Because sample loading is more readily achieved, the spray needle of the invention is appropriate for use with a fully automated system for the analysis of samples.

Droplets or plugs within multiphase microfluidic systems have rapidly gained interest as a way to manipulate samples and chemical reactions on the femtoliter to microliter scale. Chemical analysis of the plugs remains a challenge. It has been discovered that nanoliter plugs of sample separated by air or oil can be analyzed by electrospray ionization mass spectrometry when pumped directly into a fused silica nanospray emitter nozzle. Using leu-enkephalin in methanol and 1% acetic acid in water (50:50 v:v) as a model sample, we found carry-over between plugs was <0.1% and relative standard deviation of signal for a series of plugs was 3%. Detection limits were 1 nM. Sample analysis rates of 0.8 Hz were achieved by pumping 13 nL samples separated by 3 mm long air gaps in a 75 μm inner diameter tube. Analysis rates were limited by the scan time of the ion trap mass spectrometer. The system provides a robust, rapid, and information-rich method for chemical analysis of sample in segmented flow systems.

An ionization method for use with mass spectrometry or ion mobility spectrometry is a small molecule compound(s) as a matrix into which is incorporated analyte. The matrix has attributes of sublimation or evaporation when placed in vacuum at or near room temperature and produces both positive and negative charges. Placing the sample into a region of sub-atmospheric pressure, the region being in fluid communication with the vacuum of the mass spectrometer or ion mobility spectrometer, produces gas-phase ions of the analyte for mass-to-charge or drift-time analysis without use of a laser, high voltage, particle bombardment, or a heated ion transfer region. This matrix and vacuum assisted ionization process can operate from atmosphere or vacuum and produces ions from large (e.g. proteins) and small molecules (e.g. drugs) with charge states similar to those observed in electrospray ionization.

Microfluidic devices provide substances to a mass spectrometer. The microfluidic devices include first and second surfaces, at least one microchannel formed by the surfaces, and an outlet at an edge of the surfaces which is recessed back from an adjacent portion of the edge. Hydrophilic surfaces and / or hydrophobic surfaces guide substances out of the outlet. A source of electrical potential can help move substances through the microchannel, separate substances and / or provide electrospray ionization.

A multimode ionization source with improved ionization characteristics that comprises an electrospray ionization source for providing a charged aerosol, an atmospheric pressure chemical ionization (APCI) source including a corona needle having an end positioned downstream from the electrospray ionization source for producing a discharge that further ionizes the charged aerosol, an assist gas inlet positioned adjacent to the corona needle for providing assist gas, the assist gas facilitating ionization of the charged aerosol by the corona discharge, and a conduit having an orifice for receiving ions from the charged aerosol.

Electrospray ionization sources interfaced to mass spectrometers have become widely used tools in analytical applications. Processes occurring in Electrospray (ES) ionization generally include the addition or removal of a charged species such as H+ or other cation to effect ionization of a sample species. Electrospray includes ionization processes that occur in the liquid and gas phase and in both phases ionization processes require a source or sink for such charged species. Electrolyte species, that aid in oxidation or reduction reactions occurring in Electrospray ionization, are added to sample solutions in many analytical applications to increase the ion signal amplitude generated in Electrospray and detected by a mass spectrometer (MS) Electrolyte species that may be required to enhance an upstream sample preparation or separation process may be less compatible with the downstream ES processes and cause reduction in MS signal New Electrolytes have been found that increase positive and negative polarity analyte ion signal measured in ESMS analysis when compared with analyte ESMS signal achieved using more conventional electrolytes The new electrolyte species increase ES MS signal when added directly to a sample solution or when added to a second solution flow in an Electrospray membrane probe. It has also been found that running the ES membrane probe with specific Electrolytes in the second solution of the ES membrane probe have been found to enhance ESMS signal compared to using the same electrolytes directly in the sample solution being Electrosprayed The new electrolytes can be added to a reagent ion source configured in a combination Atmospheric pressure ion source to improve ionization efficiency.

A multimode ionization source includes an electrospray ionization source for providing a charged aerosol, an atmospheric pressure ionization source downstream from the electrospray ionization source for further ionizing said charged aerosol, and a mode separator, or mask, situated so as to separate a portion of the charged aerosol and prevent the portion from being exposed to the atmospheric pressure ionization source.

The invention relates to a screening method for 43 artificial synthetic pigments in an aquatic product. The method comprises the following steps: screening by virtue of quadrupole tandem time-of-flight mass spectrometry of liquid chromatogram; calling an established mass spectrometry screening database to automatically scan and retrieve in a molecular matching mode; through a C18 analytic column, carrying out gradient elution by taking an acetonitrile solution containing 0.1% of formic acid in a 5mmol / L ammonium acetate aqueous solution as a moving phase, wherein the flow rate is 0.3ml / minute; and detecting under a negative ion mode by using an electrospray ionization source, extracting a suspicious sample, purifying the sample by virtue of a matrix dispersion method, carrying out liquid chromatographic separation, quantitatively determining by virtue of an external standard method, and verifying. The screening method has the advantages that the detection method is simple and quick to operate and high in sensitivity. By adopting the matrix dispersion method to purify the sample, the interference of matrix components is effectively reduced. Misjudgment events such as false positive events are greatly reduced by virtue of the qualitative function of the quadrupole tandem time-of-flight mass spectrometry, so that the monitoring ability of the detection mechanism on the risk of the aquatic product is extremely enhanced.

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.

This invention describes an apparatus and method with a combined primary electrospray and secondary electrospray ionization source used to enhance ionization efficiency. The solid phase as well as liquid phase sampling, ionization, and detection is described.

Mass spectrometry techniques for determining the status of sepsis in an individual are provided. A biomarker profile resolved from a biological sample, taken from the individual, using a mass spectrometry technique is compared to a reference biomarker profile. A single such comparison classifies the individual as belonging to or not belonging to a reference population. The individual's biomarker profile and the reference biomarker profile comprise a plurality of ions each having a mass-to-charge ratio of about 100 Daltons to about 1000 Daltons. The plurality of ions can be detected by electrospray ionization mass spectrometry in positive mode. The comparison uses a decision rule, such as a classification tree, that determines the status of sepsis in the individual without requiring knowledge of the identity of the biomarkers in the biomarker profile from the individual and without requiring knowledge of the identity of the biomarkers in the reference biomarker profile.

Charged droplet spray is formed from a solution with all or a portion of the charged droplet spray current generated from reduction or oxidation (redox) reactions occurring on surfaces removed from the first or sample solution flow path. In one embodiment of the invention, two solution flow channels are separated by a semipermeable membrane. A first or sample solution flowing through the first solution flow channel exchanges cation or anion charged species through the semipermeable membrane with a second solution or gas flowing through the second flow channel. Charge exchange is driven by the electric field applied at the charged droplet sprayer sample solution outlet. Redox reactions occur at an electrode surface in contact with the second solution. The invention increases the control and range of the Electrospray ionization process during ES / MS operation. Alternative embodiments of the invention provide for conducting redox reactions on conductive surfaces removed from the first or sample solution flow path but not separated by semipermeable membranes.

Polyionic liquid salts are provided comprising polycationic or polyanionic molecules. Further provided are solvents comprising one or more polyionic liquid salts, and the use of such polyionic liquid salts as stationary phases in gas chromatography, and as a reagent in electrospray ionization-mass spectrometry (ESI-MS).

The field of the invention is atmospheric pressure mass spectrometry (MS), and more specifically a process and apparatus which combine infrared laser ablation with electrospray ionization (ESI).

An inexpensive electrospray mass spectrometer capable of performing measurements consecutively from the ESI mode to the cold-spray ionization mode and vice versa. The electrospray mass spectrometer has an electrospray ion source, a nebulization nozzle, and a sampling orifice. The axes of the nozzle and orifice intersect each other. The instrument has a movable cold-spray desolvation chamber. In the electrospray ionization mode, the desolvation chamber is placed off the axis of the nebulization nozzle. In the cold-spray ionization mode, the desolvation chamber is set on the axis of the nebulization nozzle.

The chemical composition of petroleum samples is measured using orbitrap mass spectrometry with electrospray ionization (ESI). The orbitrap measurement is used in a screening to determine if one or more higher resolution (but more expensive) compositional analyses are justified.

An ion source able to ionize both liquid and gaseous vapors from interfaced liquid separation techniques and a solids / liquid atmospheric pressure (AP) probe. The liquid effluents are ionized by electrospray ionization, photoionization or atmospheric pressure chemical ionization and the vapors released from a probe device placed in a heated gas stream in the AP source are ionized by a corona or Townsend electrical discharge or photoionization. The source has the ability to ionize compounds from both liquid and solid sources, which facilitates ionization of volatile and semivolatile compounds by applying heat from a gas stream as well as highly non-volatile compounds infused by electrospray or separated by liquid chromatography or capillary electrophoresis.

A method for assaying one or more immunosuppressant drug analytes in a sample derived from whole blood comprises: (a) passing the sample dissolved in a mobile phase through a length of 30 mm or less of a stationary phase of a reversed-phase chromatographic column; (b) eluting the separated analytes from the reversed-phase chromatographic column; (c) ionizing molecules of the eluted separated analytes by a heated electrospray ionization source of a mass spectrometer so as to generate a plurality of precursor ion species; (d) isolating, for each analyte, a respective one of the precursor ion species; (e) fragmenting ions of each of the isolated precursor ion species in a fragmentation cell of the mass spectrometer so as to generate a plurality of product ions therefrom; and (f) detecting, for each analyte, the presence and quantity of a respective one of the product ion species using a detector of the mass spectrometer.