Determination of Endosulfan in Water Samples Using Dispersive Liquid-liquid Micro-extraction and Experimental Design for Optimization

Water contamination due to the wide variety of pesticides used in agriculture is a global environmental pollution problem. In order to reach at sub-μgL-1 levels of detection, an efficient extraction technique is required. A simple, fast and economical method, dispersive liquid-liquid micro extraction (DLLME), followed by gas chromatography-mass spectrometry was assessed for determining endosulfan in water samples. Experimental parameters which control the performance of DLLME, such as extraction and disperser solvents type and their volumes, temperature, and salt addition were studied by experimental design. The main factors affecting the extraction efficiency, volumes of disperser and extraction solvents, were optimized by response surface method. Under optimum conditions, the method was linear over the range 0.1-50 μg/L. The enrichment factor and extraction recovery were 163.4 and 63.73, respectively. Correlation coefficient and limit of detection (LODs) are 0.9996, 20 ng/L, respectively.