Detection of Organotin Compounds in the Surface Seawater and Sediments along the Coast of Okinawa Island, Japan

Six organotin species - tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPT), diphenyltin (DPT) and monophenyltin (MPT) - were investigated along the coast of Okinawa Island, Japan. Analytical conditions for organotin compounds in seawater and in marine sediments were optimized for GC with pulsed flame photometric detector. In July 2002, samples were collected at 30 locations. Butyltin species were present in all stations, but phenyltin species can be detected in only a few stations. The TBT concentration ranged from 40.2 ng L^ Sn to ND (not detected) in the seawater, and from 172 to 1.20 ng g^ Sn (dry weight) in sediments, with the highest values closely related with shipping activity and decreasing according to the distance from potential sources. A comparative study of the concentration of organotin species in 2002 and 2003 showed an increase trend