Compound identification by mass spectrometry
AssigneeDH Technologies Development Pte. Ltd.
InventorLyle Lorrence Burton
Life of this patent
Estimating the term…
Abstract
Mass spectra are received over time for a compound of interest. A primary XIC is calculated for a primary product ion of the compound and a secondary XIC is calculated for a secondary product ion from the mass spectra. A primary value is calculated from a combination of intensities of one or more points corresponding to one or more times of a primary peak of the primary XIC and a secondary value is calculated from a combination of intensities of one or more points corresponding to the one or more times of a secondary peak of the secondary XIC. Or, the primary value is calculated as an area of a time window within the primary peak and the secondary value is calculated as an area of the time window within the secondary peak. A ratio is calculated from the primary value and the secondary value.
Claims20
A system for calculating a ratio of a chromatographic peak of a primary ion of a compound of interest to a chromatographic peak of a secondary ion, the system comprising:
- a separation device that separates and fragments or only separates the compound of interest from a sample at a plurality of different times;
- an ion source device that ionizes separated fragments of the compound of interest or only the compound of interest, producing an ion beam;
- a mass spectrometer that mass analyzes product ions of the compound of interest, or selects and fragments the compound of interest and mass analyzes the product ions of the compound of interest from the ion beam at the plurality of different times, producing a plurality of mass spectra;
- and
- a processor that:
- calculates a primary extracted ion chromatogram (XIC) for a primary product ion of the compound of interest, and calculates a secondary XIC for a secondary product ion of the compound of interest using the plurality of mass spectra,
- calculates a primary value from an intensity of one point corresponding to one time or a combination of intensities of two or more points corresponding to two or more times, but fewer than all points, of a primary peak of the primary XIC and calculates a secondary value from an intensity of one point corresponding to the one time or a combination of intensities of two or more points corresponding to the two or more times of a secondary peak of the secondary XIC, or calculates the primary value as an area of a time window within the primary peak that is less than a peak width of the primary peak and calculates the secondary value as an area of the time window within the secondary peak, wherein the secondary XIC is free of a peak finding algorithm, and
- calculates the ratio from the primary value and the secondary value.
A method for calculating a ratio of a chromatographic peak of a primary ion of a compound of interest to a chromatographic peak of a secondary ion, the method comprising:
- separating and fragmenting or only separating the compound of interest from a sample at a plurality of different times using a separation device;
- ionizing separated fragments of the compound of interest or only the compound of interest using an ion source device, producing an ion beam;
- mass analyzing product ions of the compound of interest or selecting and fragmenting the compound of interest and mass analyzing the product ions of the compound of interest from the ion beam at the plurality of different times using a mass spectrometer, producing a plurality of mass spectra
- calculating a primary extracted ion chromatogram (XIC) for a primary product ion of the compound of interest and calculating a secondary XIC for a secondary product ion of the compound of interest from the plurality of mass spectra using a processor;
- calculating a primary value from an intensity of one point corresponding to one time or a combination of intensities of two or more points corresponding to two or more times, but fewer than all points, of a primary peak of the primary XIC and calculating a secondary value from an intensity of one point corresponding to the one time or a combination of intensities of two or more points corresponding to the two or more times of a secondary peak of the secondary XIC using the processor, or calculating the primary value as an area of a time window within the primary peak that is less than a peak width of the primary peak and calculating the secondary value as an area of the time window within the secondary peak using the processor, wherein the secondary XIC is free of a peak finding algorithm;
- and
- calculating the ratio from the primary value and the secondary value using the processor.
A computer program product comprising a non-transitory and tangible computer-readable storage medium including a program with instructions being executed on a processor to perform a method for identifying a ratio of a chromatographic peak of a primary ion of a compound of interest to a chromatographic peak of a secondary ion, the method comprising:
- providing a system, wherein the system comprises one or more distinct software modules, and wherein the one or more distinct software modules comprise a measurement module and an analysis module provide appropriate antecedence basis;
- instructing a separation device to separate and fragment, or only separate the compound of interest from a sample at a plurality of different times using the measurement module;
- instructing an ion source device to ionize separated fragments of the compound of interest, or only the compound of interest using the measurement module, producing an ion beam;
- instructing a mass spectrometer to mass analyze product ions of the compound of interest or select and fragment the compound of interest and mass analyze the product ions of the compound of interest from the ion beam at the plurality of different times using the measurement module, producing a plurality of mass spectra;
- calculating a primary extracted ion chromatogram (XIC) for a primary product ion of the compound of interest, and calculating a secondary XIC for a secondary product ion of the compound of interest from the plurality of mass spectra using the analysis module;
- calculating a primary value from an intensity of one point corresponding to one time or a combination of intensities of two or more points corresponding to two or more times, but fewer than all points, of a primary peak of the primary XIC and calculating a secondary value from an intensity of one point corresponding to the one time or a combination of intensities of two or more points corresponding to the two or more times of a secondary peak of the secondary XIC using the analysis module, or calculating the primary value as an area of a time window within the primary peak that is less than a peak width of the primary peak and calculating the secondary value as an area of the time window within the secondary peak using the analysis module, wherein the secondary XIC is free of a peak finding algorithm;
- and
- calculating a ratio from the primary value and the secondary value using the analysis module.
Dependencies are inferred from the claim text.