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US 9,312,110 B2Granted
System and method for grouping precursor and fragment ions using selected ion chromatograms
AssigneeWaters Technologies Corporation
InventorsScott J. Geromanos, Jeffrey Cruz Silva, Guo-Zhong Li, Marc Victor Gorenstein
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Abstract
LC/MS data generated by an LC/MS system is analyzed to determine groupings of ions associated with originating molecules. Ions are grouped initially according to retention time, for example, using retention time or chromatographic peaks in mass chromatograms. After initial groupings are determined based on retention time, ion peak shapes are compared to determine whether ions should be excluded. Ions having peak shapes not matching other ions, or alternatively a reference peak shape, are excluded from the group.
Claims27
A method of analyzing a sample comprising:
- performing an experiment including chromatographic separation and mass spectral analysis of the sample, wherein said mass spectral analysis includes alternating multiple times within a time scale of a single chromatographic peak between a low energy mode generating primarily precursor ions and a high energy mode generating primarily fragment ions;
- obtaining low energy spectra and high energy spectra from the experiment, the low energy spectra including primarily precursor ion data for the precursor ions obtained from the low energy mode, the high energy spectra including primarily fragment ion data for the fragment ions obtained from the high energy mode;
- determining characteristics for each of the precursor ions using the low energy spectra and each of the fragment ions using the high energy spectra, the characteristics including a chromatographic retention time and a peak profile;
- and
- determining a group of any of the precursor ions and the fragment ions having corresponding chromatographic retention times and corresponding peak profiles, said group denoting a portion of the precursor ions and the fragment ions deriving from a common originating molecule.
2 more elements
A system comprising:
- a processor;
- and
- a memory including code stored therein that, when executed by the processor, performs processing that analyzes a sample, the processing comprising:
- performing an experiment including chromatographic separation and mass spectral analysis of the sample, wherein said mass spectral analysis includes alternating multiple times within a time scale of a single chromatographic peak between a low energy mode generating primarily precursor ions and a high energy mode generating primarily fragment ions;
- obtaining low energy spectra and high energy spectra from the experiment, the low energy spectra including primarily precursor ion data for the precursor ions obtained from the low energy mode, the high energy spectra including primarily fragment ion data for the fragment ions obtained from the high energy mode;
- determining characteristics for each of the precursor ions using the low energy spectra and each of the fragment ions using the high energy spectra, the characteristics including a chromatographic retention time and a peak profile;
- and
- determining a group of any of the precursor ions and the fragment ions having corresponding chromatographic retention times and corresponding peak profiles, said group denoting a portion of the precursor ions and the fragment ions deriving from a common originating molecule.
5 more elements
A system comprising:
- a first instrument that performs chromatographic separation;
- a second instrument that performs mass spectrometry;
- and
- a memory including code stored therein that, when executed by the processor, performs processing that analyzes a sample comprising:
- performing an experiment including performing chromatographic separation of the sample using the first instrument and mass spectral analysis of the sample using the second instrument, wherein said mass spectral analysis includes alternating multiple times within a time scale of a single chromatographic peak between a low energy mode generating primarily precursor ions and a high energy mode generating primarily fragment ions;
- obtaining low energy spectra and high energy spectra from the experiment, the low energy spectra including primarily precursor ion data for the precursor ions obtained from the low energy mode, the high energy spectra including primarily fragment ion data for the fragment ions obtained from the high energy mode;
- determining characteristics for each of the precursor ions using the low energy spectra and each of the fragment ions using the high energy spectra, the characteristics including a chromatographic retention time and a peak profile;
- and
- determining a group of any of the precursor ions and the fragment ions having corresponding chromatographic retention times and corresponding peak profiles, said group denoting a portion of the precursor ions and the fragment ions deriving from a common originating molecule.
6 more elements
Dependencies are inferred from the claim text.