Interactive software for interpreting and curating high-resolution electron ionization mass spectra

Gas chromatography coupled with electron ionization and high-resolution mass spectrometry (GC-EI-HRMS) has been increasingly used in analytical chemistry in recent years. At the same time, there is currently relatively little specialized software for basic interpretation of such mass spectra, taking into account the proposed structure: assigning the elemental composition to each mass spectral peak, checking the isotopic pattern of peaks. Limited functionality of this kind is available in the NIST MS Interpreter (one ”mass spectrum-structure” pair at a time) and in the MS-DIAL package. However, these software packages are mainly focused on low-resolution GC-MS and MS2, respectively. EI-MS mass spectra differ significantly from MS2 mass spectra and require special software. In this work, we propose the “gchrmsexplain” software specifically developed for this purpose. It includes both a graphical user interface and a command-line interface. Batch processing is possible. The software was applied to 6 publicly available GC-EI-HRMS data sets: RECETOX, HREI-MSDB, and others. It was shown that some of them contain low-quality mass spectra. It was demonstrated that the presented software is well-suited for the curation of such data. The software is free and available online: https://github.com/mtshn/gchrmsexplain.