Organotin compounds in surface sediments from selected fishing ports along the Chinese coast

The concentrations and species of organotin compounds (OTCs) in 52 surface sediment samples from nine fishing ports along the Chinese coast were studied. Butyltins (BTs) and phenyltins (PhTs) were derivatized using sodium tetraethylborate (NaBEt4) and determined by head-space solid-phase microextraction (HS-SPME) gas chromatography coupled with a flame photometric detector (GC-FPD). The concentrations of OTCs ranged from < 3.6 to 194 ng (Sn) g(-1) dry weight (dw) for monobutyltin (MBT), < 2.3 to 41.5 ng (Sn) g(-1) dw for dibutyltin (DBT), < 0.7 to 86.0 ng (Sn) g(-1) dw for tributyltin (TBT) and < 5.1 to 66.1 ng (Sn) g(-1) dw for monophenyltin (MPhT), respectively. The concentrations of diphenyltin (DPhT) and triphenyltin (TPhT) were below the limit of detection (LOD). BTs were the main species in the sediments except for the samples collected from Shazikou fishing port in Qingdao. The concentrations of MBT were higher than DBT and TBT. The concentrations of OTCs in the sediments varied widely among different sampling locations. The concentrations of BTs were much higher in the samples collected from fishing ports close to the South China Sea than those in coast of the East China Sea and the Yellow Sea. MPhT was prevalent in most sampling stations except for those in coast of the East China Sea. The environmental and ecotoxicological risks of TBT in most sediment samples were low.