An optimized sample preparation and analysis method for the determination of polycyclic aromatic hydrocarbons and polychlorinated biphenyls in the atmospheric bulk deposition samples

A method based on solid phase extraction (SPE), gas chromatography tandem mass spectrometry (GC-MS/MS) and gas chromatography with electron capture detector (GC-ECD) was developed for the determination of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in atmospheric deposition samples. Six indicator PCB congeners were analysed by GC-ECD equipped with two micro electron-capture detectors and two gas chromatographic columns, while 12 PAH compounds were analysed by GC-MS/MS. Solid phase extraction on silica sorbent proved suitable for accumulation of PAHs and PCBs from deposited matters. The extraction procedure was based by passing the whole sample volume through a silica cartridge with dichloromethane and n-hexane as the eluting solvents. Two different performances of a bulk collector were compared. The method was validated using field total deposited samples collected monthly over a year by bulk method at an urban background station in Zagreb, Croatia. The levels and occurrence of PCBs corresponded to global environmental pollution, with the deposition rates of Sigma 6PCBs between 6 - 28 ng m(-2) d(-1). The deposition rates of Sigma 12PAHs varied between 132 and 714 ng m(-2) d(-1) during the warm period, whereas it achieved a significantly higher range of 171 to 1069 ng m(-2) d(-1) in the cold period. (c) 2020 Elsevier B.V. All rights reserved.