Development of Directly Suspended Droplet Micro Extraction Method for Extraction of Organochlorine Pesticides in Water Samples

Abstract

A simple and efficient directly suspended droplet micro extraction in conjunction with gas chromatography-electron capture detector (GC-ECD) has been developed for extraction and determination of organochlorine pesticides (OCPs) from water samples. In this technique a micro drop of 1-dodecanol is delivered to the surface of an aqueous sample while being agitated by a stirring bar in the bulk of solution. Factors relevant to the extraction efficiency were studied and optimized. The optimized extraction conditions were extraction solvent: 1-dodecanol; extraction temperature: 60◦C; NaCl concentration: 0.5M; solvent extraction volume: 10 μL; stirring rate: 800rpm and the extraction time: 20 min. The detection limits of the method were in the range of 0.066–1.85 ngL−1, relation standard deviation (n=5) range were 0.102 - 0.964. A good linearity (r 2 ≥0.995) and a relatively broad dynamic linear range (25–2600ng.L−1) were obtained and recoveries of method were in the range of 90.729% - 102.343%. Finally, the proposed method was successfully utilized for pre concentration and determination of OCPs in different real samples. We successfully developed a method based on the DSDME technique combined with capillary GC-ECD for the analysis of OCPs in the water samples and compared with the conventional sample preparation method such as LPME.