Contents and sources of DDT impurities in dicofol formulations in Turkey.

ABSTRACT

BACKGROUND, AIM, AND SCOPE Dicofol is widely used as a pesticide in agriculture applications. Since dicofol is mainly synthesized from dichlorodiphenyltrichlorethane (DDT), it contains DDT as an impurity. The European Community has forced Prohibition Directive 79/117/EEC to reduce DDT in dicofol formulations. Specifically, DDT content in a dicofol formulation cannot exceed 0.1%. The goal of this project was to determine the DDT content in dicofol formulations used in Turkey. MATERIALS AND METHODS: Samples of all the dicofol formulations in Turkey were collected to quantify DDT and DDT-related compounds. Four replicates were used for each sample. GC/MS/MS was used to analyze p,p' and o,p' isomers of DDT, DDD, and DDE. A HPLC was used to determine p,p'-Cl-DDT concentrations. RESULTS: The total DDT content of the formulated dicofol was found between 0.3% and 14.3%. The concentration of p,p'-DDE ranged from 167 to 1,042 mg kg(-1) in dicofol samples. p,p'-DDT concentrations were found to be 32 to 183 mg kg(-1). The o,p'-DDT level ranged from 2 to 34 mg kg(-1) in the dicofol formulations analyzed. DISCUSSION: It was estimated that 617.8 kg of DDT was released from dicofol. The main impurity was identified as p,p-Cl-DDT. Based on these results, dicofol serves as a continuing source of DDT contamination. CONCLUSIONS: All DDT concentrations in dicofol samples analyzed were higher than the permitted 0.1% level of Prohibition Directive 79/117/EEC. The reduction of dicofol is critical since it serves as a continual source of DDT contamination. RECOMMENDATIONS AND PERSPECTIVES DDT has been found in soil, water, and air samples. Dicofol has been identified as a contributor to continued DDT contamination in soil and water. More studies are needed to ascertain the source of DDT in the air.