Determination of nitrated polycyclic aromatic hydrocarbons in diesel particulate-related standard reference materials by using gas chromatography/mass spectrometry with negative ion chemical ionization

Abstract

Gas chromatography/mass spectrometry (GC/MS) with negative ion chemical ionization (NICI) detection was utilized for quantitative determination of nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) in diesel particulate-related standard reference materials (SRMs). Prior to GC/MS analysis, isolation of the nitro-PAHs from the complex diesel particulate extract was accomplished using solid phase extraction (SPE) and normal-phase liquid chromatographic (LC) fractionation using an amino/cyano stationary phase. Concentrations of eight to ten mononitro-PAHs and three dinitropyrenes were determined in three diesel particulate-related SRMs: SRM 1650a Diesel Particulate Matter, SRM 1975 Diesel Particulate Extract, and SRM 2975 Diesel Particulate Matter (Industrial Forklift). The results from GC/MS NICI using two different columns (5% phenyl methylpolysiloxane and 50% phenyl methylpolysiloxane) were compared to each other and to results from two other laboratories for selected nitro-PAHs. 1-Nitropyrene was the most abundant nitro-PAHs in each of the diesel particulate SRMs (19.8+/-1.1 micro g g(-1) particle in SRM 1650a and 33.1+/-0.6 micro g g(-1) particle in SRM 2975). Three dinitropyrene isomers were measured in SRM 1975 at 0.5-1.4 micro g g(-1) extract and in SRM 2975 at 1-3 micro g g(-1) particle.

Development of analytical methods for polycyclic aromatic hydrocarbons (PAHs) in airborne particulates: A review

“…This allows the detection of low concentrations and a higher degree of selectivity than in other types of common detectors. Thus, negative ion chemical ionization mass spectrometry (NCI-MS) (Bezabeh et al, 2003;Dusek et al, 2002;Ramdahl and Urdal, 1982;Siegmund et al, 2003) and ECD (Xu and Lee, 2001) are the most widely used techniques for the analysis of oxy-and nitro-PAHs, showing the lowest limits of detection. Xu and Lee (2000) also developed a derivatization-GC/ECD analytical method to identify and quantify NPAHs in atmospheric particulate matter.…”

Atmospheric Chemistry of Polycyclic Aromatic Hydrocarbons and Related Compounds

“…1,2) These compounds are predominantly produced from a wide variety of anthropogenic sources such as the incomplete combustion of fossil fuels for industrial plants, heating, as well as diesel powered vehicles. [3][4][5] NPAHs, which generally exhibit higher mutagenicity and carcinogenicity than the parent PAHs, are also generated from atmospheric reactions of PAHs released into the gas-phase with radical species such as OH and NO 3 radicals and nitrogen oxides. [6][7][8][9][10] OPAHs and OHPAHs, which may show biological effects different from mutagenicity and carcinogenicity, are also known to be secondarily formed via oxidation of PAHs and NPAHs in the atmosphere.…”

Detection limits of electron and electron capture negative ionization-mass spectrometry for aldehydes derivatized with o-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine hydrochloride

“…In contrast to high-energy (i.e., hard ionization) EI-MS, soft ionization (e.g., ECNI) does not typically induce extensive fragmentation of a molecular ion. A negative-charge molecular ion (i.e., [M] Ϫ• ) may appear with a high abundance in an ECNI spectrum facilitating the analyte identification as well as increasing sensitivity [18]. It was observed, however, that the fragmentation of PFBHA-aldehyde negative-charge molecular ions (namely C 6 -C 10 linear aldehydes, glyoxal, methylglyoxal, and benzaldehyde) in ECNI was as extensive as that of positive-charge molecular ions in EI, perhaps due to the dominating dissociative electron capture mechanism of ionization [1,11].…”