Chromatography/mass spectrometry data processing device

Patent metadata

Field	Value
Publication number	US-2016025691-A1
Application number	US-201414339607-A
Country	US
Kind code	A1
Filing date	Jul 24, 2014
Priority date	Jul 24, 2014
Publication date	Jan 28, 2016
Grant date	—

Abstract

Using the intensity ratio of peaks on a standard mass spectrum of the target compound and peaks with the same m/z on the measured mass spectrum near the retention time of said compound, a scale factor waveform close to the chromatogram shape based on the target compound alone is computed, and m/z candidates for quantitation are extracted based on the correlation between the measured mass chromatogram of the target compound and the scale factor waveform. Furthermore, an intensity ratio is determined with reference to the m/z peaks showing the greatest scale factor on the measured mass spectrum at the measurement time point showing the greatest scale factor in the scale factor waveform, and m/z candidates for quantitation/confirmation are narrowed down based on whether they fall within an allowable range based on peak intensity ratio on the standard mass spectrum.

First claim

What is claimed is:

1 . A chromatography/mass spectrometry data processing device which analyzes and processes data having, as dimensions, mass-to-charge ratio, time and signal intensity obtained by repeatedly executing mass analysis across a predetermined mass-to-charge ratio range after separating the components in a sample in the time direction with a chromatograph, the chromatography/mass spectrometry data processing device comprising:
a) a chromatogram peak shape estimation unit which, using the intensity ratio of the intensity of a peak on a standard mass spectrum of a target compound which is the object of analysis and the intensity of peaks having the same mass-to-charge ratio on the measured mass spectrum at various measurement time points near the retention time of said target compound, estimates the shape of chromatogram peaks due to said target compound from which the influence of overlap of impurity components has been eliminated; b) a chromatogram peak correlation determination unit which determines the correlation between the shape of the chromatogram peaks obtained by said chromatogram peak shape estimation unit and the peaks of said target compound on the measured mass chromatogram obtained at each mass-to-charge ratio; c) a mass spectrum peak purity determination unit which determines the mass spectrum peaks originating solely from the target compound based on the intensity ratio of multiple peaks on the standard mass spectrum of said target compound and the intensity ratio of multiple peaks having the same mass-to-charge ratio on the measured mass spectrum of the target compound at a specific measurement time point; and d) a mass-to-charge ratio derivation unit which, using the determination results of said chromatogram peak correlation determination unit and the determination results of said mass spectrum peak purity determination unit, derives a mass-to-charge ratio as a confirmation mass-to-charge ratio and/or quantitation mass-to-charge ratio used for quantitating said target compound.

2 . The chromatography/mass spectrometry data processing device as described in claim 1 ,
characterized in that said chromatogram peak shape estimation unit determines the intensity ratio Ps/Pr (where Ps: peak intensity on measured mass spectrum; Pr: peak intensity on standard mass spectrum) of peaks having the same mass-to-charge ratio on the measured mass spectrum at a given measurement time point for the mass-to-charge ratio of all or some of the peaks on the standard mass spectrum of said target compound, takes the smallest of the multiple intensity ratios Ps/Pr as the scale factor at that measurement time point, and arranges the scale factors determined at each measurement time point in time series order to estimate the shape of the chromatogram peak of said target compound.

3 . The chromatography/mass spectrometry data processing device as described in claim 1 ,
characterized in that, when the intensity of all or some of the peaks on the standard mass spectrum of said target compound is multiplied by a constant scaling factor and compared to the intensity of the peak having the same mass-to-charge ratio on the measured mass spectrum at a given measurement time point, said chromatogram peak shape estimation unit determines a constant scale factor such that the former intensity does not exceed the latter and arranges the scale factors determined at each measurement time point in time series order to estimate the shape of the chromatogram peaks of said target compound.

4 . The chromatography/mass spectrometry data processing device as described in any one of claim 1 ,
characterized in that said mass spectrum peak purity determination unit determines the reference measurement time point and reference mass-to-charge ratio which give the peak top of the chromatogram peak obtained by said chromatogram peak shape estimation unit, and taking as reference the ratio of the peak intensity for the reference mass-to-charge ratio on the standard mass spectrum of said target compound to the peak intensity at an arbitrary mass-to-charge ratio, determines if the ratio of peak intensity for the reference mass-to-charge ratio on the measured mass spectrum at said reference measurement time point to the peak intensity at said arbitrary mass-to-charge ratio falls within a predetermined range in relation to said reference, and thereby judges if the peak for the arbitrary mass-to-charge ratio is a mass spectrum peak originating solely from said target compound.

5 . The chromatography/mass spectrometry data processing device as described in any one of claim 2 ,
characterized in that said mass spectrum peak purity determination unit determines the reference measurement time point and reference mass-to-charge ratio which give the peak top of the chromatogram peak obtained by said chromatogram peak shape estimation unit, and taking as reference the ratio of the peak intensity for the reference mass-to-charge ratio on the standard mass spectrum of said target compound to the peak intensity at an arbitrary mass-to-charge ratio, determines if the ratio of peak intensity for the reference mass-to-charge ratio on the measured mass spectrum at said reference measurement time point to the peak intensity at said arbitrary mass-to-charge ratio falls within a predetermined range in relation to said reference, and thereby judges if the peak for the arbitrary mass-to-charge ratio is a mass spectrum peak originating solely from said target compound.

6 . The chromatography/mass spectrometry data processing device as described in any one of claim 3 ,
characterized in that said mass spectrum peak purity determination unit determines the reference measurement time point and reference mass-to-charge ratio which give the peak top of the chromatogram peak obtained by said chromatogram peak shape estimation unit, and taking as reference the ratio of the peak intensity for the reference mass-to-charge ratio on the standard mass spectrum of said target compound to the peak intensity at an arbitrary mass-to-charge ratio, determines if the ratio of peak intensity for the reference mass-to-charge ratio on the measured mass spectrum at said reference measurement time point to the peak intensity at said arbitrary mass-to-charge ratio falls within a predetermined range in relation to said reference, and thereby judges if the peak for the arbitrary mass-to-charge ratio is a mass spectrum peak originating solely from said target compound.

7 . A chromatography/mass spectrometry data processing method in which data having, as dimensions, mass-to-charge ratio, time and signal intensity is obtained by repeatedly executing mass analysis across a predetermined mass-to-charge ratio range after separating the components in a sample in the time direction with a chromatograph, the chromatography/mass spectrometry data method comprising:
a) using the intensity ratio of the intensity of a peak on a standard mass spectrum of a target compound which is the object of analysis and the intensity of peaks having the same mass-to-charge ratio on the measured mass spectrum at various measurement time points near the retention time of said target compound, estimating the shape of chromatogram peaks due to said target compound from which the influence of overlap of impurity components has been eliminated; b) determining the correlation between the shape of the obtained chromatogram peaks and the peaks of said target compound on the measured mass chromatogram obtained at each mass-to-charge ratio; c) determining the mass spectrum peaks originating solely from the target compound based on the intensity ratio of multiple peaks on the standard mass spectrum of said target compound and the intensity ratio of multiple peaks having the same mass-

Assignees

• Shimadzu Corp

Inventors

• Taneda Katsuyuki

Classifications

• G01N30/72 Primary

  Mass spectrometers {(mass spectrometers per se H01J49/00)} · CPC title

• H01J49/0027

  Methods for using particle spectrometers · CPC title

• H01J49/0036 Primary

  Step by step routines describing the handling of the data generated during a measurement · CPC title

• H01J49/0095

  Particular arrangements for generating, introducing or analyzing both positive and negative analyte ions (ion/ion reactions H01J49/0072) · CPC title

• H01J49/26

  Mass spectrometers or separator tubes · CPC title