Temperature-assisted ionic liquid dispersive liquid-liquid microextraction combined with high performance liquid chromatography for the determination of PCBs and PBDEs in water and urine samples

Abstract

We report a multi-residue pretreatment technique, termed temperature-assisted ionic liquid dispersive liquid-liquid microextraction, and demonstrate its application to simultaneous extraction of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). An ionic liquid was used as the extraction solvent and dispersed into the liquid sample (water, urine) with the help of methanol and at elevated temperature. Parameters such as extraction solvent and its volume, disperser solvent and its volume, extraction time, centrifugation time, salt addition, extraction temperature and sample pH were optimized. Under the optimized conditions, an up to 278-fold enrichment factor and an >83.4% extraction recovery were obtained. A linear relationship is obtained in the range of 0.5–500 ng mL−1. The limits of detection (at S/N = 3) and relative standard deviations (for n = 5) range from 0.1 to 0.4 ng mL−1 and from 1.0% to 5.6%, respectively. The recoveries for water and urine samples additionally spiked with PCBs and PBDEs are between 81.0 and 127.1% and 84.0 and 110.3%, respectively. The method was successfully applied to the determination of PCBs and PBDEs in real river water and in human urine samples.