Residues in fish exposed to sublethal doses of endosulfan and fish collected from cotton growing area

Abstract

A one step extraction and cleanup procedure for determining endosulfan in fish was investigated. Minced Fish was mixed with trisodium citrate, disodium hydrogen orthophosphate and sodium sulphate into a dry powdery mixture, which was eluted through silicic acid and alumina with a mixture of dichloromethane and hexane. The eluate was concentrated and chromatographed on GLC using an EC detector without further cleanup. Three species of fresh water fish exposed to 0.7–16 μg/ litre^‐1 technical grade endosulfan in tanks for various periods of time were found to concentrate both a and J3 endosulfan and metabolise them to sulfate, diol, ether and lactone. Fish collected from Gwydir River in the cotton growing area in summer (Dec. 1986‐Feb. 1987) were found to contain endosulfan residues suggesting endosulfan is quite stable in the environment and can cause residues.