A Novel Approach of Matching Mass-to-Charge Ratio for Compound Identification in Gas Chromatography–Mass Spectrometry

: Background: Gas chromatography-mass spectrometry (GC-MS) is one of the most widely used analytical techniques for analyzing chemical or biological samples in many fields. One of the most important approaches for the identification of compound in GC-MS is to compare an experimental mass spectrum with a compound recorded in a reference spectral library through a spectrum-matching algorithm. Objective: To develop a novel method to speed up compound identification. Method: In this study, a method based on m/z matching is proposed. We selected the highest m/z values and m/z values corresponding to the largest peak intensities of a mass spectrum and stepwise modified the matching threshold (MTh) based on the principle of local optimum in the pre-search process. The performance of the approach is evaluated using the mass spectral library maintained by the National Institute of Standards and Technology as a reference library and repetitive mass spectra as query spectra. Results: Compared with two-step spectral library pre-search and "ten peaks," the method based on m/z matching has higher accuracy, smaller number of remaining (missing) spectra, and shorter computational time. Conclusions: Therefore, the method can effectively speed up compound identification. Highlights: A method based on m/z matching is proposed. The accuracy is higher, the number of remaining spectra is less, and the computational time is shorter.