Mass spectrometry systems and methods for analyses on lipid and other ions using a unique workflow

Patent metadata

Field	Value
Publication number	US-9347917-B2
Application number	US-201314388309-A
Country	US
Kind code	B2
Filing date	Mar 28, 2013
Priority date	Mar 28, 2012
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

The applicants' teachings provide in some aspects methods and apparatus for mass spectrometric analysis that identify the location of carbon-carbon double bonds, if any, in an analyte by (1) obtaining the m/z ratio of the intact analyte ions, (2) subjecting these ions to collision-induced dissociation and (3) determining relationships between masses and/or mass-to-charge ratios of the intact analyte ions and the fragments produced by such collision-induced dissociation. The methods and apparatus selectively subject analyte ions to ozone-induced dissociation based on those relationships and determine location(s) of carbon-carbon double bonds, if any, from reaction products of ozone-induced dissociation.

First claim

In view of the foregoing, what we claim is:

1. A method for mass analysis comprising:
generating ions of an analyte using an ion source;
selecting a subset of ions received from the ion source with a mass filter that is coupled in an ion flow path;
transmitting the subset of ions through a reaction region that is coupled in an ion flow path with the mass filter and that is filled with any of an inert gas that is used to induce collision-induced dissociation of ions received from the mass filter and ozone that is used to induce ozone-induced dissociation of such ions;
detecting the subset of ions using an ion analyzer that is coupled in an ion flow path with the reaction region and that separates any of ions and fragments received from the reaction region as a function of mass-to-charge ratio (m/z) and that generates an output representing a spectrum thereof; and
employing the ion source, mass filter, reaction region and ion analyzer to identify the location of carbon-carbon double bonds, if any, in the analyte by (1) subjecting ions of the analyte generated by the ion source to mass analysis without any fragmentation or reaction, (2) subjecting ions of the analyte generated by the ion source to collision-induced dissociation in the reaction region, (3) determining relationships between masses and/or mass-to-charge ratios of the ions and/or fragments produced by such collision-induced dissociation, (4) selectively subjecting, based on those relationships, ions generated by the ion source to ozone-induced dissociation in the reaction region, and (5) determining the location(s) of carbon-carbon double bonds, if any, from reaction products of such ozone-induced dissociation.

2. The method of claim 1 , wherein the mass filter comprises any of a quadrupole mass spectrometer and an ion trapping device.

3. The method of claim 1 , wherein the mass filter selects a said subset from within a predetermined mass-to-charge ratio range.

4. The method of claim 1 , wherein a gas mixture is formed comprising ozone and the inert gas for performing collision-induced dissociation.

5. The method of claim 4 , wherein the the inert gas comprises one of helium, neon, nitrogen, argon, xenon, and air.

6. The method of claim 1 , wherein the ion source, mass filter, reaction region and ion analyzer operate such that analyte ions within a range of mass-to-charge values are transmitted through the reaction region without undergoing fragmentation or reaction and are extracted to the ion analyzer.

7. The method of claim 1 , wherein the ion source, mass filter, reaction region and ion analyzer operate such that analyte ions within the range of mass-to-charge values are transmitted through the reaction region such that the analyte ions are subjected to collisions with the gas mixture to affect collision-induced dissociation of the analyte ions.

8. The method of claim 7 , wherein the ion source, mass filter, reaction region and ion analyzer operate such that ions within the reaction region are extracted from the reaction region, with the ion detector detecting the ions of the analyte of interest after they have undergone collisions in the reactive region, wherein a mass-to-charge ratio of the ions of the analyte of interest is determined from the ion analyzer.

9. The method of claim 8 , wherein the mass spectrum of the intact analyte ions is compared with the mass spectrum of the collision-induced fragments to determine a specific mass difference between any of the fragment ions and the intact analyte ions or on a specific collision-induced fragment ion to indicate the presence of one or more carbon-carbon double bonds.

10. The method of claim 9 , wherein the ion source, mass filter, reaction region and ion analyzer operate such that the analyte ions identified as containing at least one carbon-carbon double bond are transmitted by the mass filter substantially separating analyte ions in a range of mass-to-charge ratio values.

11. The method in claim 10 , wherein the ion source, mass filter, reaction region and ion analyzer operate such that the identified analyte ions transmitted by the mass filter are trapped in the reaction region for a period of time wherein the analyte ions undergo a reaction with ozone.

12. The method of claim 11 , wherein the ion source, mass filter, reaction region and ion analyzer operate such that all ions contained in the reaction region are extracted from the reaction region after a period of time, with the ion detector detecting the ions of the analyte of interest after they have undergone collisions in the reactive region, wherein a mass-to-charge ratio of the ions of the analyte of interest is determined from the ion analyzer.

13. An apparatus for mass analysis comprising:
an ion source to generate ions of an analyte;
a mass filter that is coupled in an ion flow path with the ion source to select a subset of ions received from the ion source;
a reaction region that is coupled in an ion flow path with the mass filter and that is filled with any of an inert gas that is used to induce collision-induced dissociation of ions received from the mass filter and ozone that is used to induce ozone-induced dissociation of such ions;
an ion analyzer that is coupled in an ion flow path with the reaction region and that separates any of ions and fragments received from the reaction region as a function of mass-to-charge ratio (m/z) and that generates an output representing a spectrum thereof;
the ion source, mass filter, reaction region and ion analyzer operate to identify the location of carbon-carbon double bonds, if any, in the analyte by (1) subjecting ions of the analyte generated by the ion source to mass analysis without any fragmentation or reaction, (2) subjecting ions of the analyte generated by the ion source to collision-induced dissociation in the reaction region, (3) determining relationships between masses and/or mass-to-charge ratios of the ions and/or fragments produced by such collision-induced dissociation, (4) selectively subjecting, based on those relationships, ions generated by the ion source to ozone-induced dissociation in the reaction region, and (5) determining the location(s) of carbon-carbon double bonds, if any, from reaction products of such ozone-induced dissociation.

14. The apparatus of claim 13 , wherein the mass filter comprises any of a quadrupole mass spectrometer and an ion trapping device.

15. The apparatus of claim 13 , wherein the mass filter selects a said subset from within a predetermined mass-to-charge ratio range.

16. The apparatus of claim 13 , wherein a gas mixture is formed comprising ozone and the inert gas for performing collision-induced dissociation.

17. The apparatus of claim 16 , wherein the inert gas comprises one of helium, neon, nitrogen, argon, xenon, and air.

Assignees

• Dh Technolgies Dev Pte Ltd
• Univ Wollongong
• Dh Technologies Dev Pte Ltd

Inventors

• Campbell John Lawrence
• Duchoslav Eva
• Blanksby Stephen
• Mitchell Todd

Classifications

• H01J49/0031 Primary

  Step by step routines describing the use of the apparatus (H01J49/0081 takes precedence) · CPC title

• H01J49/005

  by collision with gas, e.g. by introducing gas or by accelerating ions with an electric field · CPC title

• G01N27/62 Primary

  by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode · CPC title