Apparatus and method for processing of mass spectrometry data

• US 20070023642A1
• Filed: 06/24/2005
• Published: 02/01/2007
• Est. Priority Date: 06/24/2005
• Status: Active Grant

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Altmayer, Lee
• Granted Patent: US 7,488,935 B2
• Time in Patent Office: Days
• US Class Current: 250/288
• CPC Class Codes: G06F 2218/08 Feature extraction
• CPC Class Codes: H01J 49/0036 Step by step routines describing the handling of the data generated during a measurement

Abstract

A mass spectrometry system is described. The mass spectrometry system includes an ion source to ionize a sample stream, a detector positioned downstream with respect to the ion source to acquire mass spectrometry data of the sample stream, and a data analyzer connected to the detector. The data analyzer includes a chromatogram generator to process the mass spectrometry data to derive a chromatogram, a data point selector to apply a selection criterion to the chromatogram to select data points from the chromatogram, and a peak discriminator to apply a discriminating criterion to the data points to detect a peak in the chromatogram, wherein the peak is indicative of a presence of an analyte in the sample stream. A computer-readable medium for a mass spectrometry system and a method of processing mass spectrometry data are also described..

Claims

1. A mass spectrometry system, comprising:

(a) an ion source to ionize a sample stream;

(b) a detector positioned downstream with respect to the ion source to acquire mass spectrometry data of the sample stream; and

(c) a data analyzer connected to the detector and comprising;

(i) a chromatogram generator to process the mass spectrometry data to derive a chromatogram;

(ii) a data point selector to apply a selection criterion to the chromatogram to select data points from the chromatogram; and

(iii) a peak discriminator to apply a discriminating criterion to the data points to detect a peak in the chromatogram, wherein the peak is indicative of a presence of an analyte in the sample stream.

2. The mass spectrometry system of claim 1, wherein the chromatogram corresponds to one of a total ion chromatogram, a base peak chromatogram, and a mass chromatogram.

3. The mass spectrometry system of claim 1, wherein the data point selector is configured to apply the selection criterion to select the data points based on magnitudes of the data points.

4. The mass spectrometry system of claim 1, wherein the peak discriminator is configured to apply a matched filter to identify a first set of data points from the data points as corresponding to the peak.

5. The mass spectrometry system of claim 4, wherein the peak discriminator is configured to apply the matched filter to identify a second set of data points from the data points as corresponding to a spike.

6. The mass spectrometry system of claim 1, wherein the data analyzer further comprises a peak area calculator to calculate an area of the peak, wherein the area of the peak is indicative of an amount of ions produced from the analyte.

7. The mass spectrometry system of claim 6, wherein the data points correspond to first data points from the chromatogram, and the peak area calculator is configured to apply an analysis to second data points from the chromatogram to derive a baseline.

8. A computer-readable medium for a mass spectrometry system, comprising:

(a) code to select data points from a chromatogram based on magnitudes of the data points; and

(b) code to apply a discriminating criterion to the data points to detect a peak in the chromatogram, wherein the peak is indicative of a presence of an analyte.

9. The computer-readable medium of claim 8, wherein the chromatogram comprises a sequence of data points, and the code in (a) comprises code to select the data points from the sequence of data points based on the magnitudes of the data points with respect to a lower threshold value.

10. The computer-readable medium of claim 8, wherein the chromatogram comprises a sequence of data points, and the code in (a) comprises code to select the data points from the sequence of data points based on the magnitudes of the data points with respect to magnitudes of remaining data points from the sequence of data points.

11. The computer-readable medium of claim 10, wherein the sequence of data points are arranged based on one of scan number and time, and the code to select the data points from the sequence of data points comprises:

code to arrange the sequence of data points based on magnitude to derive a reordered sequence of data points; and

code to select the data points from the reordered sequence of data points.

12. The computer-readable medium of claim 8, wherein the code in (b) comprises code to apply a matched filter to the data points.

13. The computer-readable medium of claim 8, wherein the code in (b) comprises code to identify a first set of data points from the data points as corresponding to the peak.

14. The computer-readable medium of claim 13, wherein the code in (b) further comprises code to identify a second set of data points from the data points as corresponding to a spike.

15. The computer-readable medium of claim 8, wherein the data points correspond to first data points from the chromatogram, and the computer-readable medium further comprises:

code to apply a regression analysis to second data points from the chromatogram to derive a baseline; and

code to calculate an area of the peak based on the baseline, wherein the area of the peak is indicative of an amount of the analyte.

16. A method of processing mass spectrometry data, comprising:

(a) defining a matched filter based on a sequence of data points; and

(b) applying the matched filter to the sequence of data points to identify a first set of data points from the sequence of data points as corresponding to a peak, wherein the peak is indicative of a presence of an analyte.

17. The method of claim 16, wherein a width of the matched filter corresponds to an expected width of the peak.

18. The method of claim 16, wherein the defining the matched filter in (a) comprises deriving an offset value of the matched filter based on the sequence of data points.

19. The method of claim 18, wherein the offset value comprises an estimated baseline value associated with the sequence of data points.

20. The method of claim 16, wherein the applying the matched filter in (b) comprises identifying a second set of data points from the sequence of data points as corresponding to a spike.

21. The method of claim 16, further comprising selecting data points from the sequence of data points based on magnitudes of the data points, and wherein the applying the matched filter in (b) comprises applying the matched filter to the data points to identify the first set of data points from the data points as corresponding to the peak.