System and method for isotopic signature and mass analysis
View Patent ↗Mass intensity values, isotopic ratios and exact mass differences between isotopes may be obtained and analyzed to determine if there are one or more masses of interest. In one implementation, a method will look among the mass intensity values for peaks of interest. The mass intensity values, representative of isotopic signatures, will be compared to a criteria in order to determine which of the masses are of interest. Although the invention is not so limited, examples of such criteria include mass intensity values above a specified threshold, within a certain ratio of another mass intensity value, and/or separation between the masses themselves. Optionally, a tolerance may be applied to the criteria. If masses are found to be of interest, MS/MS can automatically be triggered for one or all of the masses of interest, when an analyzing system such as an LC-MS-MS, GC-MS-MS or MALDI-MS-MS system is used.
1. In an isotopic signature with mass analysis system, a method comprising the steps of:
obtaining a plurality of mass intensity values corresponding to a plurality of masses;
comparing said plurality of mass intensity values to a criteria to determine whether any of said plurality of masses are of interest; and
directing that a mass spectrometry process be performed on any of said plurality of masses that are of interest.
2. The method of claim 1 , wherein, before said step of comparing, the step of obtaining at least a portion of said criteria by the use of a user interface.
3. The method of claim 1 , wherein said isotopic signature analysis system is a liquid chromatography-mass spectrometry-mass spectrometry system.
4. The method of claim 1 , wherein said criteria comprises a first mass difference between a first mass and a second mass.
5. The method of claim 4 , wherein said criteria further comprises a second mass difference between said first mass and a third mass.
6. The method of claim 4 , wherein said criteria further comprises a peak threshold.
7. The method of claim 4 , wherein said criteria further comprises a first ratio between an intensity of said first mass value and an intensity of said second mass value.
8. The method of claim 1 , wherein said criteria comprises a first ratio between an intensity of a first mass value and an intensity of a second mass value.
9. The method of claim 8 , wherein said criteria further comprises a second ratio between said intensity of said first mass value and an intensity of a third mass value.
10. The method of claim 8 , wherein said criteria further comprises a peak threshold.
11. The method of claim 1 , wherein said criteria comprises a peak threshold.
12. The method of claim 1 , wherein said plurality of masses of said step of obtaining are exact masses.
13. A medium holding computer executable steps for a method, said method comprising the steps of:
obtaining a plurality of mass intensity values corresponding to a plurality of masses;
comparing said plurality of mass intensity values to a criteria to determine whether any of said plurality of masses are of interest; and
directing that a mass spectrometry process be performed on any of said plurality of masses that are of interest.
14. The medium of claim 13 , wherein, before said step of comparing, the step of obtaining at least a portion of said criteria by the use of a user interface.
15. The medium of claim 13 , wherein said criteria comprises a first mass difference between a first mass and a second mass.
16. The medium of claim 13 , wherein said criteria comprises a first ratio between an intensity of a first mass value and an intensity of a second mass value.
17. The medium of claim 13 , wherein said criteria comprises a peak threshold.
18. The medium of claim 13 , wherein said plurality of masses of said step of obtaining are exact masses.
19. A system for analysis of isotopic signature with exact mass, said system comprising:
an electronic device adapted to obtain a plurality of mass intensity values corresponding to a plurality of masses and compare said plurality of mass intensity values to a criteria to determine whether any of said plurality of masses are of interest; and
a second stage mass separation device to perform mass spectrometry on any of said plurality of masses that are of interest.
20. The system of claim 19 , wherein said criteria comprises a first mass difference between a first mass and a second mass.
21. The system of claim 19 , wherein said criteria comprises a first ratio between an intensity of a first mass value and an intensity of a second mass value.
22. The system of claim 19 , wherein said criteria comprises a peak threshold.
23. The system of claim 19 , wherein said plurality of masses are exact masses.