A sensitive determination method for trace bisphenol A in bottled water and wastewater samples: Binary solvent liquid phase microextraction-quadrupole isotope dilution-gas chromatography-mass spectrometry

A sensitive, accurate and precise methodology was established for the preconcentration and determination of bisphenol A in bottled water and wastewater samples at trace levels. A binary solvent liquid phase micro extraction (BSLPME) method was optimized to extract bisphenol A before determination by gas chromatography mass spectrometry (GC-MS). The type of binary solvent/disperser solvent, vortex period and mode of adding extraction and disperser solvent mixture to aqueous solution were determined by univariate optimization. Three significant parameters including volume of binary solvent, volume of dispersive solvent and ratio of binary solvent were optimized using Box-Behnken Design. Low limit of detection (0.30 ng/g) and limit of quantitation (0.99 ng/g) values were recorded for the BSLPME-GC-MS method. Hence, 173 times enhancement in the detection limit of the GC-MS system was achieved by the developed microextraction method. Quadrupole isotope dilution (ID4) strategy was used to augment the extraction method to achieve high accuracy and precision. When the developed BSLPME method was combined with the ID4 strategy, bottled water and wastewater samples spiked at approximately 200 ng/g recorded excellent recovery results of 100.3 +/- 0.4% and 100.0 +/- 0.5%, respectively. Therefore, accurate and precise determination of bisphenol A at trace levels was achieved by a low cost, rapid and green analytical method.