Organotin compounds in surface and pore waters of Ganga Plain in the Kanpur-Unnao industrial region, India

Organotin compounds (OTCs) belong to those chemicals most toxic to the aqua tic organisms which are deliberately introduced into the aquatic system thr ough anthropogenic activities. Various species of organotin compounds were detected in surface and pore waters of the Ganga Plain in Kanpur-Unnao indu strial region in pre- and post-Monsoon periods of 1995. The extraction of t hese compounds was performed using a method of direct aqueous phase in situ ethylation with sodium tetraethylborate (NaBEt4). After extraction into he xane, they were detected by GC-MIP-AED. The water of this area is contamina ted with dimethyltin (DMT), monobutyltin (MBT), dibutyltin (DBT) and tribut yltin (TBT) compounds. Concentrations of these compounds in surface water o f the pre-Monsoon period of 1995 range from 2.1 to 70.1 ng Sn/l for MET, 1. 7-101.1 for DBT and 2.9-19.8 for TBT, whereas in pore water; 9.7-23.5 ng Sn /l for MET, 11.2-18.0 for DBT and 8.7-32.6 for TBT. However, in the post-Mo nsoon period of 1995, surface water shows considerable decrease in concentr ations: DMT below detection-1.8 ng Sn/l, DBT 3.0-5.4, TBT 3.1-3.6 and MBT i s below detection. This study is a preliminary documentation of water pollu tion by OTCs in the Kanpur-Unnao region of the Ganga Plain and suggests the necessity of further detailed OTCs studies in other regions of the Ganga P lain. (C) 1998 Elsevier Science B.V. All rights reserved.