A simple derivatization and highly sensitive gas chromatography-mass spectrometry method for the determination of glycidol and 2-/3-monochloropropanediol in heated tobacco product aerosol

Glycidol, 3-chloropropane-1,2-diol (3-MCPD), and 2-chloropropane-1,3-diol (2-MCPD), known as thermal processing contaminants, have been identified in heated tobacco product (HTP) aerosol, raising significant health concerns. Therefore, it is necessary to establish a quantitative analytical method for the release of them. In this study, ethyl acetate was used to extract the aerosol of HTP collected by Cambridge filter pad (CFP), the extract was derivatized with heptafluorobutyrylimidazole (HFBI), washed and dried before being analyzed by gas chromatography-mass spectrometry (GC-MS). The retention index and mass spectral characteristics of glycidol-HFBI derivative were characterized for the first time. The limits of quantification (LOQs) for glycidol, 3-MCPD and 2-MCPD were 58.32, 37.51 and 55.88 ng/cigarette respectively;the intra- and inter-day precision were less than 10% with recoveries ranging from 89% to 111%. The analysis results of eight domestic and foreign HTPs showed that: (1) The three target compounds were detected in all eight samples, indicating their widespread presence in HTP aerosol. (2) Significant variations in per-puff emission among samples suggested formulation and heating mode significantly impact glycidol and MCPDs release. (3) Glycidol and 3-MCPD were the major released substances, accounting for about 80% of the total three compounds emission. This study establishes a sensitive, reliable method for determining glycidol, 3-MCPD and 2-MCPD in HTP aerosol, providing critical technical support for health risk assessments.