SIMULTANEOUS DETERMINATION OF BENTAZONE A ND BENSULFRONMETHYL IN ENVIRONMENTAL WATER BY HPLC AFTER SOLVENT-EXTRACTION

A simultaneous determination method for bentazone (BTZ) and bensulfron methyl (BSM) in environmental water was developed. The pH of 1000 ml o f water sample was adjusted to 0.5 similar to 2.0 with hydrochloric ac id, and then the water sample was extracted with three 150 ml portions of ether. The ether extract was concentrated to 5 ml with a rotary ev aporator, and dried-up under an air stream. The residue was dissolved with 3 ml of acetonitrile. The clean-up procedure of the acetonitrile solution was developed using a Accu BOND C-18 cartridge. Recoveries of BTZ and BSM were measured by HPLC with photodiode array detector. Rec overies of BTZ and BSM from pure water were about 90%. Those from lake and river waters were 77 similar to 88%, The coefficient of variation was in the range 0.4 similar to 3.2% for BTZ and 2.0 similar to 5.3% for BSM and the detection limit was 0.5 mu g/l for BTZ and 1.0 mu g/l for BSM when 1000 ml of sample was used. The present method was succes sfully applied to the determination of BTZ and BSM in lake, ground, se a and river waters.