Distribution of butyltin species in sediment samples collected from Saigon habours in Ho Chi Minh city

Abstract

In this study, the distribution of tributyltin (TBT) and its degradation products, dibutyltin –DBT and monobutyltin – MBT in sediment sample collected adjacent Saigon habours was studied using gas chromatographic separation/ mass spectrometric detection. Sediment samples at 12 sites along the Saigon river were taken during dry and raining seasons in 2014 and 2015. Butyltin species were extracted from sediment matrix using HBr-tropolone into dichloromethane followed by ethylation with NaB(C2H5)4 in hexane. The reliability of the analytical method for butyltin species was evaluated by the use of the certified reference BCR-646 material. The concentrations of TBT, DBT and MBT in sediment samples were <0.1–2.81 ng/g, <0.1–4.3 ng/g and <0.2–8.4 ng/g (as Sn, dw). Butyltin species in sediment samples at sites within the habour area were higher than those at sites far upstreams or down-streams of the habours. Low values in TBT/(DBT+MBT) ratios revealed that the discharge of TBT from fouling paint was low at recent years.