GC/MS and DART-MS as complementary methods for investigating the effects of weathering on chemical profiles of ignitable liquids: A case study for paint thinner

• Published in: Forensic chemistry 2023-05, Vol.33, p.100478, Article 100478
• Main Authors: Perna, Shruthi, Dedicatoria, Briza Marie, Chong, Ngee Sing, Zhang, Mengliang
• Format: Article
• Language: English
• Subjects: Arson; Chemometrics; DART-MS; Ignitable liquids; Paint thinner
• ISSN: 2468-1709; 2468-1709
• DOI: 10.1016/j.forc.2023.100478

[Display omitted] •Polymeric compounds were identified as markers for paint thinner by DART-MS.•Weathering extent and temperature factors were evaluated by the ANOVA-PCA method.•DART-MS can provide discriminative information for ignitable liquid samples.•DART-MS can complement the GC/MS method by the detection of less volatile compounds. In this study, gas chromatography/mass spectrometry (GC/MS) and direct analysis in real time mass spectrometry (DART-MS) were used to analyze paint thinner samples weathered under different conditions. As GC/MS total ion chromatograms (TIC) of weathered paint thinner samples varied significantly due to the disparate evaporation rates of organic compounds in the mixture, DART-MS spectra have shown more consistent profiles among different samples. The distinctive ion clusters identified in the DART-MS spectra were attributed to the less volatile glycol ethers and polymeric compounds with alkyl chains in the paint thinner samples. Analysis of variance-principal component analysis (ANOVA-PCA) was applied to study the contributions of weathering degree and temperature factors to the total variance of GC/MS TIC and DART-MS spectral datasets and found that both factors played significant roles in the weathering process (p