Determination of endocrine disrupting chemicals in water samples by dispersive liquid-liquid microextraction combined with liquid chromatography-fluorescence detection

An analytical method based on dispersive liquid-liquid microextraction (DLLME) followed by liquid chromatography (LC)-fluorescence detection was developed to determine endocrine disruptors in environmental water samples. Four endocrine disrupting chemicals (EDCs) including bisphenol A, 4-tert-octylphenol, 4-octylphenol, and 4-nonylphenol were extracted and pre-concentrated by DLLME. Total analysis including extraction and LC analysis was achieved within 15 min. Extraction parameters such as types of extraction and dispersive solvents, volumes of extraction and dispersive solvents, extraction time, and NaCl concentration were optimized. Calibration curves for all EDCs were linear over a wide range with correlation coefficient (r²) ≥ 0. 9989. Intra- and inter-day precisions as relative standard deviations were less than 5. 4 and 13. 3%, respectively. Limit of detection ranged between 0. 2 and 1. 0 μg/L and limit of quantification ranged between 0. 6 and 3. 2 μg/L. The proposed method was applied to analysis of the EDCs in various samples including tap water and commercial bottled water and no EDCs were found in the tested samples.