Application of Three Phase Hollow Fiber LPME Using an Ionic Liquid as Supported Phase for Preconcentration of Bisphenol A and Diethylstilbestrol from Water Sample with HPLC Detection

Abstract

A new method for the determination of trace bisphenol A (BPA) and diethylstilbestrol (DES) in water samples has been developed by using three phase hollow fiber liquid-phase microextraction (HF-LPME) and an ionic liquid (IL, 1-Octyl-3-methylimidazolium hexafluorophosphate, [C8MIM][PF6]) as supported phase (IL-HF-LPME) combined with high performance liquid chromatography/ultraviolet spectrophotometry (HPLC/UV). The optimized microextraction conditions were as follows: [C8MIM][PF6] was used as the extraction solvent, pH 10 NaOH solution, 5 µL, as acceptor phase; 20 mL water sample with NaCl (5%, w/v) as donor phase and the extraction time was 30 min (stirring rate 200 rpm, 25°C). Under the optimal extraction conditions, the proposed method offered: good linearity range, 0.30–100 µg L−1, with correlation coefficients (r 2) of 0.9996 and 0.9988; low detection limit, 0.20 and 0.05 µg L−1 (S/N = 3) for BPA and DES, respectively; good reproducibility (relative standard deviation, RSD, 7.28% and 8.45%, respectively, n = 5); high enrichment factor, 850 and 624, respectively. The method was used to analyze real water samples, and satisfactory recoveries (75.4–99.2%) were obtained, which confirmed that the developed method was simple and environmentally friendly for the determination of BPA and DES in aquatic systems. Meanwhile, it was found that humic acid had no obvious influence on enrichment factor.