Abstract:
Sea water samples collected at different depths from 10 stations along the Clifton beach of Karachi Coast were analyzed for dissolved/dispersed polyaromatic and aliphatic hydrocarbons (PAHs and AHs) by GC and GC-MS. Sampling was performed in august 2003, just after the Tasman Spirit oil spill and in august 2003. Levels of total polycyclic aromatic hydrocarbon (PAHs) and aliphatic hydrocarbons (AHs) were 8.20-26.35 µg L−1 (Σ 16 PAHs) and 5.23-21.005 µg L−1 (Σ 16 AHs), respectively. Values decreased later on till lower than 0.02-0.25 ug L−1 possibly representing the background level of the region, exhibited lower concentrations that ranged from 0.02-0.05 µg L−1 (Av. 0.15 µg L−1 Σ 16 PAHs and 0.05–0.2 µg L−1 Σ 14 aliphatic hydrocarbons) with decreasing to 0.07 µg L−1 of PAHs with depth in the water. In September 2005, the concentrations were rather uniform, averaging 0.05 µg L−1 (Σ 16 PAHs) and 4.08 µg L−1 Σ 14 aliphatic hydrocarbons.
