Vortex-assisted liquid-liquid microextraction of bisphenol S prior to its determination by HPLC with UV detection

Vortex-assisted liquid-liquid microextraction (VALLME) for the rapid extraction of trace bisphenol S (BPS) in environmental water is presented. In order to simplify the procedure, an in-house fabricated glass dropper with different internal diameters of the two ends is exploited. The solidification-melt step was cut in VALLME by means of the in-house fabricated glass dropper. After extraction with 2-ethylhexanol, BPS was detected by high performance liquid chromatography (HPLC) with ultraviolet (UV) detection. Factors such as type and volume of extraction solvent, extraction time, sample pH and ionic strength were evaluated. Under optimized conditions, the linearity range varied from 0.10 to 50 mu g L-1 with a squared regression coefficient r(2) of 0.9995. The relative standard deviation (RSD) is 2.3 % (n = 7). The limit of detection (LOD) and limit of quantification (LOQ) are 0.02 and 0.06 mu g L-1, respectively. The presented method was employed for the determination of BPS in real water samples. The relative recoveries are 81.8-87.3 % for the two real water samples. The method is shown to be economical, fast and can be routinely performed.