Structure Analysis of Polymer Pyrolyzate by Pyrolysis GC-TOFMS and AI -A Case Study of AI Library Containing in silico Pyrolyzate
Introduction
We have developed msFineAnalysis AI which has an automated structural analysis method [1] (hereafter referred to as AI structural analysis) that combines data from a time-of-flight mass spectrometer (TOFMS), a high mass resolution GC-MS, and mass spectrum prediction by deep learning, as a solution for unknown compound analysis. This software contains a database (DB) of structural formulas and predicted EI mass spectra of approximately 100 million compounds obtained from the PubChem DB (hereinafter referred to as the AI library). By utilizing the molecular formula information determined by integrated analysis [2], it is possible to quickly estimate the structural formula of an unknown compound.
The pyrolysis GC-MS method is a widely utilized technique for the analysis of solid polymer samples, such as resins. A significant number of the pyrolyzates observed in pyrolysis GC-MS have not been registered in commercially available electron ionization (EI) mass spectrum databases. We attempted an analysis using the AI library and confirmed that the structural analysis of unknown compounds in acrylic resin can be performed with high accuracy (MSTips No.389). However, some oligomer components, such as trimers, lacked a correct structural formula in the AI library. This may be attributed to the limited number of structural formulas registered in the PubChem DB for polymer pyrolyzates.
Consequently, a novel AI library was developed, encompassing predicted EI mass spectra of approximately 25 million pyrolyzates. This library was derived from the exhaustive generation of pyrolyzate structure formulas by in silico. In 2024, we have released msFineAnalysis AI ver. 2 with a new AI library for 120 million compounds, including polymer pyrolyzates.
In this MSTips, we report a case study of analysis using the AI library including in silico pyrolyzates equipped with msFineAnalysis AI ver. 2.