Determination of estrogens in water samples using dispersive liquid liquid microextraction and high performance liquid chromatography.

A new method for the analysis of estrogens including estrone (E1), 17b- estradiol (E2) and diethylstilbestrol (DES) in aqueous samples was performed using dispersive liquid liquid microextraction (DLLME) and high- performance liquid chromatography (HPLC). In order to optimize DLLME some important parameters such as type and volume of extraction and disperser solvent, extraction time, ionic strength and pH of sample were studied and optimum condition was obtained. Under optimum condition (extraction solvent: 80 µL CCl4; dispersive solvent: 1.25 mL acetone; NaCl: 12% (w/w) and pH of sample = 10.0), the enrichment factors and extraction recoveries were 71.0-78.5 and 85.2-94.2 respectively. Linearity was observed in the range of 0.02-500.0 µg L-1 for DES and 0.03-500.0 µg L-1 for E1 and E2. Limits of detection were 0.008 µg L-1 for DES and 0.010 µg L-1 for E1 and E2. The relative standard deviations (RSDs) for determination of estrogens in water were in the range of 2.4-3.2% (n = 5).