GC MS/MS METHOD FOR POLYCYCLIC AROMATIC HYDROCARBONS ANALYSIS IN AMBIENT AIR PM2.5

Abstract

A large number of studies have been dedicated to the development of methods for qualitative and quantitative determination of polycyclic aromatic hydrocarbons (PAHs), present in ambient air particulate matter (PM). However, due to the complex matrix and low atmospheric concentrations of PAHs, their assessment is still a challenge for the scientific community. In general, chromatographic techniques, such as GS/MS, are the commonly employed analytical methods for determination of PAHs. A mass spectrometer is typically utilized in full scan or selected ion monitoring (SIM) modes. However, the complexity of the samples and the presence of numerous isomers of alkylated and high molecular mass compounds, could affect the sensitivity and selectivity of mass spectrometric (MS) analysis in SIM mode and be a source of serious experimental errors. To reduce such errors, it is required to include an additional
clean-up step and/or to use more selective and even specific detection techniques. 
This study proposes a GC MS/MS method in multiple reaction monitoring (MRM) mode for quantification of 16 U.S. Environmental Protection Agency priority PAHs plus coronene, perylene and benzo[e]pyrene in PM with aerodynamic diameter below 2.5 μm. Prior to analysis collected samples were processed through an optimized sample preparation procedure: i) ultrasonicated extraction with an appropriate solvent, ii) drying and cleaning via column chromatography and iii) concentration by nitrogen purging. The accuracy of the method was evaluated by spiking Whatman® QM-A quartz-fiber filters with different working standards containing PAHs analytes. Linearity was assessed based on the coefficient of determination and Fisher test. LODs and LOQs varied, respectively in the range of 0.29 - 0.69 pg m-3 and 0.87 - 2.09 pg m-3. The suggested method is compared to a previously developed SIM method and has proven to be more superior.