Use of windowed mass spectrometry data for retention time determination or confirmation

摘要

A scan of a separating sample is received by a mass spectrometer at each interval of a plurality of intervals. The spectrometer performs at each interval one or more mass spectrometry scans. The scans have one or more sequential mass window widths in order to span an entire mass range at each interval and produce a collection of spectra for the entire mass range for the plurality of intervals. One or more peaks at one or more different intervals in the collection of spectra are identified for a fragment ion. A mass spectrum of the entire mass range is retrieved for each interval of each peak. Values for one or more ion characteristics of a mass-to-charge ratio peak in the mass spectrum corresponding to each peak are compared to one or more known values for the fragment ion. Each peak is scored based on the comparison.

主权项

1. A system for scoring peaks of a known compound of interest from a collection of mass spectra, comprising:
a separation device that separates one or more compounds from a sample mixture; a mass spectrometer that performs at each time interval of a plurality of time intervals one or more mass spectrometry scans on the separating sample mixture using one or more sequential mass window widths in order to span an entire mass range producing a mass spectrum for each sequential mass window width, one or more mass spectra for the entire mass range for each time interval of the plurality of time intervals and a collection of mass spectra for the plurality of time intervals; and a processor that
(a) selects a fragment ion of a known compound,(b) calculates an extracted ion chromatogram (XIC) for the fragment ion from the collection of mass spectra, wherein the XIC includes an intensity of the fragment ion for each time interval of the plurality of time intervals, and(c) if two or more XIC peaks corresponding to the fragment ion are found in the XIC at two or more different time intervals, obtains a mass spectrum of the entire mass range from the collection of mass spectra for each of the two or more different time intervals, producing two or more entire mass range mass spectra, compares values of one or more ion characteristics of a mass-to-charge ratio (m/z) peak of the fragment ion in each entire mass range mass spectrum of the two or more entire mass range mass spectra to one or more known values for the fragment ion, and bases a score of each XIC peak of the two or more XIC peaks of the fragment ion on the results of the comparison.