Pollution Levels of 16 Priority PAHs in the Major Rivers of Southern Thailand
This study involved the determination of 16 priority PAHs in river water samples collected from the 4 major rivers in the area of southernmost of Thailand. Solid phase extraction (SPE) technique was successfully applied for PAHs extraction from water samples, as this technique offers several advantages over normal liquid-liquid extraction such as efficient isolation and pre-concentration. The extraction of water samples were carried out by validated C-18 SPE cartridges. The cartridge was dried by nitrogen gas before being eluted with a solvent mixture of hexane and acetone (1:1 ratio). The analytes were quantified by SPB-5 capillary column gas chromatography (GC-FID). Percentage recovery of 16 PAHs standards were in the range of 70.24±4.22 to 115.37±6.15 % which were within the acceptable ranges of US-EPA protocol. The commonly detected PAH compounds in river water samples of this study were acenaphthylene, anthracene, fluoranthene and benzo[k]fluoranthene at the concentration range of 0.02-0.10, 0.02-1.83, 0.05-19.50 and 0.09-10.11 ug/mL, respectively. The PAHs presented in water samples were mostly comprised 4-5 fused benzene rings, which reflecting that anthropogenic sources are among the possible origin of these organic pollutants that discharged into the rivers. The detail of determinative method together with analytical results and possible sources of these pollutants will be presented.