Characterization of a multianalyte GC-MS/MS procedure for detecting and quantifying polycyclic aromatic hydrocarbons (PAHs) and PAH derivatives from air particulate matter for an improved risk assessment.

A correct description of the concentration and distribution of particle bound polycyclic aromatic hydrocarbons is important for risk assessment of atmospheric particulate matter. A new targeted GC-MS/MS method was developed for analyzing 64 PAHs including compounds with a molecular weight >300, as well as nitro-, methyl-, oxy- and hydroxyl derivatives in a single analysis. The instrumental LOD ranged between 0.03 and 0.7 pg/µL for PAHs, 0.2-7.9 pg/µL for hydroxyl and oxy PAHs, 0.1-7.4 pg/µL for nitro PAHs and 0.06-0.3 pg/µL for methyl-PAHs. As an example for the relevance of this method samples of PM10 were collected at six sampling sites in Medellin, Colombia, extracted and the concentration of 64 compounds was determined. The 16 PAHs from the EPA priority list contributed only from 54% to 69% to the sum of all analyzed compounds, PAH with high molecular weight accounted for 8.8%-18.9%. Benzo(a)pyrene equivalents (BaPeq) were calculated for the estimation of the life time cancer (LCR). The LCR according to the samples ranged from 2.75 × 10-5 to 1.4 × 10-4 by a calculation with toxic equivalent factors (TEF) and 5.7 × 10-5 to 3.8 × 10-4 with potency equivalent factor (PEF). By using the new relative potency factors (RPF) recommended by US Environmental Protection Agency (U.S.EPA) the LCR ranged from 1.3 × 10-4 to 7.2 × 10-4. Hence, it was around six times higher than the well-known TEF. The novel method enables the reliable quantification of a more comprehensive set of PAHs bound on PM and thus will facilitate and improve the risk assessment of them.