Determination of Estrogens in Environmental Aqueous Samples Using Dispersive Liquid-Liquid Microextraction and HPLC/UV-Vis System

The objective of this study was to optimize dispersive liquid-liquid microextraction (DLLME) parameters for simultaneous sample preparation of five steroidal estrogens from environmental aqueous samples: estrone (E1), 17-estradiol (E2), 17-estradiol (E2), 17 -ethinylestradiol (EE2), and estriol (E3). Estrogens from an aqueous sample were extracted and concentrated simultaneously using dispersive and extraction solvents, and chromatographic separation and quantitative analysis were performed using an HPLC/UV-vis system. The optimum parameters, such as a suitable combination of dispersion and extraction solvent, ionic strength, and sample pH were determined. The optimized parameters resulted in increased enrichment factors (EF = 28.4 similar to 69.4). From the established extraction conditions, the limits of detection and quantification in the spiked samples were in the concentration ranges of 0.03-0.07 and 0.10-0.23mg/L, respectively. The method produced linear calibration curves with correlation coefficients (r(2)) of 0.9990-0.9995 in the 0.10-8.00mg/L concentration range. The relative recovery and relative standard deviation (RSD) values in the calibration ranges were 99.1-116.6% and 0.6-4.2%, respectively. The proposed method, which is fast, simple, inexpensive, and environment friendly, can be applied in effective and simultaneous analysis of five steroidal estrogens from environmental aquatic samples.