Method Of Mass Spectrometry

• US 20120326019A1
• Filed: 02/08/2010
• Published: 12/27/2012
• Est. Priority Date: 02/06/2009
• Status: Active Grant

• Current Assignee: Micromass UK Ltd (Waters Corporation)
• Original Assignee: Micromass UK Ltd (Waters Corporation)
• Inventors: Richardson, Keith, Claude, Emmanuelle, Snel, Marten F., Vissers, Johannes Petrus Cornelis
• Granted Patent: US 8,426,808 B2
• Time in Patent Office: Days
• US Class Current: 250/282
• CPC Class Codes: G01N 33/6848 Methods of protein analysis involving mass spectrometry
• CPC Class Codes: H01J 49/0004 Imaging particle spectrometry
• CPC Class Codes: H01J 49/0027 Methods for using particle spectrometers

Abstract

This invention comprises a method of imaging of a substrate in which a sample of interest is first ionized at multiple known positions whereafter a mass spectrum of the ionized sample at each of the multiple known positions is produced using a Mass Spectrometer. An overall spectrum for the whole sample is then created, and a number of peaks within the overall spectrum is selected. A scan distribution for at least some of the selected peaks is created, and the scan distributions are compared to identify correlations between different analytes within the sample.

Claims

1. A method of analysis of data produced from the imaging of a substrate comprising the steps of:

ionizing a sample of interest at multiple predetermined positions upon the sample,

producing a mass spectrum of the ionized sample at each of said multiple predetermined positions using a Mass Analyser,

creating an overall spectrum for the whole sample,

selecting a number of peaks within the overall spectrum,

creating a scan distribution for at least some of said selected peaks, and

comparing the scan distributions to identify correlations between different analytes within the sample.

2. A method as claimed in claim 1 wherein each predetermined position is identifiable by a set of coordinates such that the ionized sample is produced from said predetermined position.

3. A method as claimed in claim 1 or 2 wherein said Mass Analyser is a Time of Flight Mass Analyser.

4. A method as claimed in claims 1-3 wherein said ionisation of sample is performed using MALDI.

5. A method as claimed in any of the preceding claims, further comprising the step of generating IMS data for the ions produced at each predetermined position.

6. A method as claimed in any of the preceding claims, further comprising the step of generating MSMS data for the ions produced at each predetermined position

7. A method as claimed in any of the preceding claims, further comprising the step of removing minor variations in spectral noise by subtraction of X% of the intensity of the peaks

8. A method as claimed in claim 7, wherein X is a value up to 15%

9. A method as claimed in claim 8, wherein X is in the range 1-10%.

10. A method as claimed in claim 9, wherein X is in the range 3-7%

11. A method as claimed in any of the preceding claims, wherein said scan distributions are normalised to scale peaks relative to each other.

12. A method as claimed in any of the preceding claims, further comprising filtering said overall mass spectral data to perform background subtraction.

13. A method as claimed in any of the preceding claims, wherein the substrate is a tissue sample.

14. A method as claimed in claim 13 for the analysis of information or products relating to drugs and drug metabolites within said tissue information

15. A method as claimed in any preceding claim wherein said comparison of scan distributions comprises performing Principal Component Analysis.

16. A method of analysis of data produced from the imaging of a substrate substantially as hereinbefore described.