title: Modified ion source triple quadrupole mass spectrometer gas chromatograph for polycyclic aromatic hydrocarbon analyses.
abstract: We describe modified gas chromatography electron-impact/triple-quadrupole mass spectrometry (GC-EI/MS/MS) utilizing a newly developed hydrogen-injected self-cleaning ion source and modified 9mm extractor lens. This instrument, with optimized parameters, achieves quantitative separation of 62 polycyclic aromatic hydrocarbons (PAHs). Existing methods historically limited rigorous identification and quantification to a small subset, such as the 16 PAHs the US EPA has defined as priority pollutants. Without the critical source and extractor lens modifications, the off-the-shelf GC-EI/MS/MS system was unsuitable for complex PAH analysis. Separations were enhanced by increased gas flow, a complex GC temperature profile incorporating multiple isothermal periods, specific ramp rates, and a PAH-optimized column. Typical determinations with our refined GC-EI/MS/MS have a large linear range of 1-10,000pgμl(-1) and detection limits of <2pgμl(-1). Included in the 62 PAHs, multiple-reaction-monitoring (MRM) mode enabled GC-EI/MS/MS identification and quantitation of several constituents of the MW 302 PAH isomers. Using calibration standards, values determined were within 5% of true values over many months. Standard curve r(2) values were typically >0.998, exceptional for compounds which are archetypally difficult. With this method benzo[a]fluorene, benzo[b]fluorene, benzo[c]fluorene were fully separated as was benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[j]fluoranthene. Chrysene and triphenylene, were sufficiently separated to allow accurate quantitation. Mean limits of detection (LODs) across all PAHs were 1.02±0.84pgμl(-1) with indeno[1,2,3-c,d] pyrene having the lowest LOD at 0.26pgμl(-1) and only two analytes above 2.0pgμl(-1); acenaphthalene (2.33pgμl(-1)) and dibenzo[a,e]pyrene (6.44pgμl(-1)).
authors.affiliation: Department of Environmental and Molecular Toxicology, Corvallis, OR 97331, USA. Electronic address: kim.anderson@oregonstate.edu.
authors.forename: Kim A
authors.initials: KA
authors.lastname: Anderson
authors.affiliation: Agilent Technologies, Wilmington, DE 19808, United States.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Szelewski
authors.affiliation: Department of Environmental and Molecular Toxicology, Corvallis, OR 97331, USA.
authors.forename: Glenn
authors.initials: G
authors.lastname: Wilson
authors.affiliation: Agilent Technologies, Wilmington, DE 19808, United States.
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Quimby
authors.affiliation: Department of Environmental and Molecular Toxicology, Corvallis, OR 97331, USA.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Hoffman
mesh_terms: D005449:Fluorenes / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D053719:Tandem Mass Spectrometry
chemical_list: D005449:Fluorenes; D011084:Polycyclic Aromatic Hydrocarbons
keywords: 302 MW PAHs; Alkyl-PAHs; Alkylated PAHs; Benzo[a]fluorene; Benzo[b]fluorene; Benzo[c]fluorene; Dibenzo[a,l]pyrene; GC/MS/MS