Determination of aqueous bisphenol A and tetrabromobisphenol A using molecular-complex-based liquid-liquid microextraction

A sample preparation method for the extraction of bisphenol A (BPA) and tetrabromobisphenol A (TBBPA), potential endocrine-disrupting chemicals common in manufacturing, from environmental water samples was established by means of molecular-complex-based liquid-liquid microextraction coupled to high-performance liquid chromatography with diode array and mass spectrometric detection. In this method, tributyl phosphate acts as an extractant of BPA and TBBPA via hydrogen bond interactions. Additionally, no dispersants are needed. Attenuated total reflection Fourier transform infrared spectroscopy provides robust evidence for the formation of hydrogen bonds between the extractant and phenols in the molecular complexes, which supports the experimental results. Under optimised conditions, calibration plots were linear in the range of 0.05–2 μg mL − 1 , and detection limits ranged from 0.16 to 0.23 ng mL − 1 . The relative standard deviations of intra-day and inter-day repeatability were in the ranges of 3.5–4.9% and 5.1–6.8%, respectively, and recoveries ranged from 84.5 to 105.6%. The method we developed has been successfully employed in the measurement of BPA and TBBPA in four aqueous environmental samples.