[Determination of trace estrogens in cosmetic water by liquid-phase microextraction coupled with high performance...

Liquid-phase microextraction (LPME) was introduced to establish a two-phase system in solvent microextraction with the integrated features of sampling, extraction, concentration and injection in a single step. It was proved that this process is a fast, effective and low-cost sample preparative method and widely used in biomedical, environmental and food analysis, as well as in other fields. In this study, a rapid method for the determination of trace estrogens (ethinyl estradiol, estradiol, estriol, and estrone) in cosmetic water by LPME coupled with high performance liquid chromatography (HPLC) was developed. The extraction conditions of LPME, such as extraction solvent, solvent volume, stirring speed, extraction time, pH value and salt concentration of the donor phase, were optimized. The enrichment factors of the estrogens was from 247 to 343. The linear detection ranges of the method were from 2 to 200 mircrog/L with the detection limits from 0. 4 to 1. 0 microg/L. The recoveries ranged from 101. 2% to 114. 9% and the relative standard deviations were less than 7. 5% for cosmetic water samples. The method is suitable for the determination of trace estrogenic compounds in cosmetic watersamples.