Spectrum library screening method aiming at mass spectrograms of mixtures

Abstract

The invention discloses a spectrum library screening method aiming at mass spectrograms of mixtures. The spectrum library screening method comprises the following steps of: with mixtures which always generate a common eluting peak during chromatographic separation as substances to be detected, screening similarities of a two-dimensional mass spectrogram and a standard mass spectrum library, matching a fragment ion peak of which the fragment ion peak kurtosis ranks in the front of the mass spectrogram of the mixtures with a fragment ion peak of the mass spectrogram of each substance in a spectrum library, and putting the substance of which the fragment ion peak is matched with that of the mass spectrogram of each substance in the spectrum library into a screening library; comparing X-axes and corresponding Y-axes of the molecular weights and the molecular ion peaks of the substances in the spectrum library with those of the mixture, and removing the substances of which the X-axes and corresponding Y-axes of the molecular weights and the molecular ion peaks are not matched with those of the mixture from the screening library; and finding out ratios, which are the same as the kurtosis ratios of the fragment ion peaks with the biggest kurtosis of the molecular ion peaks and fragment ion peaks which are near the molecular ion peaks, from the mass spectrogram of the substances to be detected by taking the positions of the molecular ion peaks in the spectrum library as a reference, and arranging the ratios of the found ratios to the kurtosis ratios from small to large to form a matching table for the substances in the screening library and the substances to be detected. By using the library screening method, dozens or hundreds of types of possible components can be quickly positioned, so that library retrieval and screening are realized, and the defects caused by low separating capacity of an instrument are overcome.

Description

technical field [0001] The invention relates to a spectral library screening method for mass spectrograms of mixed substances. Background technique [0002] In GC / MS analysis, for complex matrix samples, a chromatographic peak may be the result of overlapping of several components and matrix background ions, therefore, the maximum kurtosis in the mass spectrum is not a single component but multiple components ion peak. A mass spectral library search may give poor matches and cannot directly identify all the individual components that make up a mixed mass spectrum. [0003] Current mass spectrometry instrument workstations, ie computer systems, control instrument operation, sampling, storage, and retrieval of mass spectra. After the mass spectrometry is done, the workstation system can compare the newly obtained spectrum of unknown substances with the mass spectra of more than 200,000 known substances in the spectrum library, and find out the closest spectra in the spectrum...

AI Technical Summary

Problems solved by technology

However, when multiple substances cannot be effectively separated and form a mixture with overlapping mass spectra, the substance components cannot be retrieved effectively and quickly

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