Determination of atmospheric polycyclic aromatic hydrocarbons using accelerated solvent extraction

An accelerated solvent extraction (ASE) method has been developed for the determination of polycyclic aromatic hydrocarbons (PAHs) present in both atmospheric particulate and gaseous phases in this study. Extraction para-meters such as the combination of solvents, extraction temperature, and static extraction time were investigated and optimized. Effective extraction was achieved using a 3:1 mixture of n-hexane and acetone as extraction solvents at 100 C in 30min for all the compounds studied. The optimized extraction method was compared with conventional extraction methods and validated using National Institute of Standards and Technology (NIST)-certified standard refer-ence material (SRM) 1649a. The recoveries obtained for certified 12 PAHs were in the range of 82-126% with relative standard deviation (RSD) between 6 and 28%. The validated ASE technique was used followed by gas chromatography-mass spectrometry (GC-MS) for the determination of PAHs distributed between gaseous and particulate phases in the atmosphere of Singapore. Total average concentrations of PAHs in air samples were 33.54±19.32 ng m^-3, with 4.72±2.80 ng m^-3 in particulate phase and28.82±16.92 ng m^-3 in gaseous phase, respectively. The results obtained from this study are compared to those reported from other areas of the world.