Analytical Instrument Documents

MSTips No. 535

In GC-MS qualitative analysis, NIST database searching using the electron ionization (EI) mass spectral library provided by the National Institute of Standards and Technology (NIST) is widely used for compound identification. However, when identification is based solely on matching factors obtained from the NIST database search, multiple plausible candidates may be returned, or an incorrect compound may be selected as the identification result. In such cases, confirmation of molecular ions and other molecular mass ions using soft ionization techniques, such as photoionization (PI) and chemical ionization (CI), is effective.

To automate the above analytical workflow, we released msFineAnalysis iQ in 2021, a software package that automatically integrates and analyzes EI and SI data acquired using a gas chromatograph quadrupole mass spectrometer (GC-QMS). In msFineAnalysis iQ, highly reliable qualitative identification results can be obtained through Integrated Analysis, which combines NIST database search results based on EI mass spectra with molecular ion analysis of SI mass spectra. However, Integrated Analysis in msFineAnalysis iQ is based on NIST database searching. As a result, structural elucidation of compounds not registered in the database still requires manual interpretation, and the analysis of unknown compounds remains a considerable challenge.

To address the challenges associated with manual structural elucidation using GC-QMS data, we developed msFineAnalysis IQ, which incorporates a structural elucidation approach based on deep learning-assisted mass spectrum prediction (AI Structure Analysis). Accordingly, the product name was changed from msFineAnalysis iQ to msFineAnalysis IQ to reflect the incorporation of AI technology. This application note introduces the AI Structure Analysis function in msFineAnalysis IQ.