Quantification of complex polycyclic aromatic hydrocarbon mixtures in standard reference materials using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry

Abstract

This research is the first to quantify complex PAH mixtures in NIST SRMs using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/ToF-MS), with and without extract cleanup, and reports previously unidentified PAH isomers in the NIST SRMs. We tested a novel, high orthogonality GC column combination (LC-50×NSP-35), as well as with a commonly used column combination (Rtx-5ms×Rxi-17) for the quantification of a complex mixture of 85 different PAHs, including parent (PAHs), alkyl- (MPAHs), nitro- (NPAHs), oxy- (OPAHs), thio- (SPAHs), bromo- (BrPAHs), and chloro-PAHs (ClPAHs) in extracts from two standard reference materials: NIST SRM1650b (diesel particulate matter), with cleanup and NIST SRM1975 (diesel particulate extract), with and without extract cleanup. The LC-50×NSP-35 column combination resulted in an average absolute percent difference of 33.8%, 62.2% and 30.8% compared to the NIST certified PAH concentrations for NIST SRM1650b, NIST SRM1975 with cleanup and NIST SRM1975 without cleanup, while the Rtx-5ms×Rxi-17 resulted in an absolute percent difference of 38.6%, 67.2% and 79.6% for NIST SRM1650b, NIST SRM1975 with cleanup and NIST SRM1975 without cleanup, respectively. This GC×GC/ToF-MS method increases the number of PAHs detected and quantified in complex environmental extracts using a single chromatographic run. Without clean-up, 7 additional compounds were detected and quantified in NIST SRM1975 using the LC-50×NSP-35 column combination. These results suggest that the use of the LC-50×NSP-35 column combination in GC×GC/ToF-MS not only results in better chromatographic resolution and greater orthogonality for the separation of complex PAH mixtures, but can also be used for the accurate quantification of complex PAH mixtures in environmental extracts without cleanup.

Aerobic Bioremediation of PAH Contaminated Soil Results in Increased Genotoxicity and Developmental Toxicity

“…While the formation of polar transformation products merits attention due to their potential accumulation and toxicity, 11,52,56,71 their likely increased bioavailability needs to be accounted for as well. 11,72 Future work will focus on identifying, characterizing, and quantifying the potential hydroxylated and carboxylated 3- and 4-ring PAH transformation products responsible for the increased genotoxicity and developmental toxicity post-bioremediation using non-targeted comprehensive two dimensional gas chromatography coupled to time of flight mass spectrometry (GCxGC/ToF-MS) 19,73 (with and without derivatization) and liquid chromatography-tandem mass spectrometry (LC/MS-MS). 74 …”

Analytical Methods for Determination of Polycyclic Aromatic Hydrocarbons (PAHs) — A Historical Perspective on the 16 U.S. EPA Priority Pollutant PAHs

“…As the first to quantify PAHs in a reference material (SRM 1649a), they demonstrated "acceptable" comparison to the certified Downloaded by [New York University] at 01: 45 18 June 2015 values and noted that the methods required further optimization (145). Simonich and coworkers (146,147) evaluated several combinations of stationary phases/columns in GC x GC, including the shape selective liquid crystalline phase, to quantify 85 different PAHs, alkyl-PAHs, oxy-PAHs, PASHs, and halogenated-PAHs in two diesel particulate SRMs (SRM 1975 and SRM 1650b). Using GC x GC these authors reported agreement with the SRM certified values and the identification of numerous additional PACs using only one chromatographic run.…”

Analysis of Parent/Nitrated Polycyclic Aromatic Hydrocarbons in Particulate Matter 2.5 Based on Femtosecond Ionization Mass Spectrometry

“…Therefore, high concentrations of such PAHs pose a carcinogenic risk to the general population [2]. The organic compounds associated with PAHs can be classified mainly to parent (PPAH), nitro (NPAH), hydroxyl (OHPAH), and methyl (MPAH) PAH types [3]. Among them, PPAH are present in the highest concentration, but NPAH pose the highest carcinogenic risk.…”