Cloud point extraction coupled with HPLC-DAD for the determination of genistein and daidzein in river water

Abstract

Applying cloud-point extraction (CPE) as a preconcentration method for the determination of trace level pollutants has gained increased attention in recent years. This work aimed at developing an analytical method for the determination of genistein (GEN) and daidzein (DAI) in environmental water samples by the use of high-performance liquid chromatography separation and diode array detection (HPLC-DAD). We selected the non-ionic surfactant Triton X-114 as the extraction solvent. The parameters such as the concentrations of Triton X-114 and Na₂SO₄, equilibration temperature, equilibration time and centrifugation time which affect extraction efficiency were evaluated and optimized. The developed method showed overall good performance with enrichment factors of 80, 144 for GEN and DAI, respectively, and detection limits of 3.77 ng mL⁻¹ for GEN and 2.23 ng mL⁻¹ for DAI in 30 mL water sample under the optimum conditions. The recoveries for GEN and DAI were all above 91% and RSD for GEN and DAI were 7.41% and 7.87%, respectively. Our study shows that the proposed method can be successfully adopted for the determination of trace amounts of GEN and DAI in river water.