Total alkylated polycyclic aromatic hydrocarbon characterization and quantitative comparison of selected ion monitoring versus full scan gas chromatography/mass spectrometry based on spectral deconvolution

• Published in: Journal of Chromatography A 2008-09, Vol.1205 (1), p.109-116
• Main Authors: Zeigler, Christian, MacNamara, Kevin, Wang, Zhendi, Robbat, Albert
• Format: Article
• Language: English
• Subjects: Alkylated PAH; Analytical chemistry; Applied sciences; Automated sequential 2D GC–GC/MS; Chemistry; Chromatographic methods and physical methods associated with chromatography; Crude oil, natural gas and petroleum products; Diesel; Energy; Environmental forensics; Environmental Monitoring - methods; Exact sciences and technology; Forensic Sciences - methods; Fuels; Gas chromatographic methods; Gas Chromatography-Mass Spectrometry - methods; Gasoline - analysis; Ion Signature deconvolution software; Petroleum; Polycyclic Aromatic Hydrocarbons - analysis; Prospecting and production of crude oil, natural gas, oil shales and tar sands
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2008.07.086

Quantitative information of alkylated PAH is frequently used in forensic investigations to characterize petroleum releases and fate in the environment. Interference from a complex matrix often obviates target compound quantitation. Using single ion SIM or a single mass spectral pattern to analyze these homologs should result in either over- or underestimating their concentration. To confirm this hypothesis, a library of C 1–C 4 alkylated PAH fragmentation patterns were made from automated sequential two-dimensional GC–GC/MS data and the Ion Signature deconvolution software. Based on these patterns, 1D GC/MS data was compared using single ion extraction and one fragmentation pattern per homolog against data obtained from those peaks whose scans met the spectral deconvolution criteria. Significant overestimation occurs when a single ion is used to extract peak signal for C 4-naphthalene, C 1-fluorene, and the C 1- to C 3-dibenzothiophenes. In contrast, C 2-naphthalene, C 2-fluorene, C 3-phenanthrene, and C 1-dibenzothiophene were underestimated by >50% when one fragmentation pattern per homolog was used. The Ion Signature deconvolution software makes it easy to interpret mass spectrometry data, especially in complex environmental samples like diesel fuel.