A miniaturised analytical protocol for highly sensitive determination of bisphenol A in bottled drinking water

Abstract

This paper proposes a novel, fast, reliable and miniaturised analytical protocol for highly sensitive determination of bisphenol A (BPA) in bottled drinking water. This hybrid approach involves a lucid and expeditious combination of micro-extraction in packed syringe (MEPS) with high performance liquid chromatography coupled to an ultra-violet detector (HPLC-UV). The method was developed, optimised and validated for the determination of BPA in commercial bottled drinking water with remarkable sensitivity to picogram quantities of BPA (ppt level). The important parameters of the MEPS procedure affecting the extraction efficiency were optimized and 50 cycles of draw–eject of the sample with a speed of 10 μl s⁻¹ gave a maximum peak area, with a time of <5 min. Compared with conventional solid-phase extraction, this MEPS procedure required less extraction time, sample volume and consumption of organic solvents. This method demonstrated high linearity within the range of 1–500 pg ml⁻¹ for BPA (R² > 0.998). Precision studies showed % RSD values less than 2% for BPA in all the selected concentrations. The percentage recoveries of BPA were in the range of 97.50–97.57. The limit of detection (LOD) and limit of quantification (LOQ) were 0.0416 pg ml⁻¹ and 0.1248 pg ml⁻¹ for BPA, respectively. The proposed validated method was successfully applied for the quantitative analysis of BPA in real water and beverage samples to the level of 5.40 pg ml⁻¹ to 14.22 pg ml⁻¹, with an acceptable RSD (%) in the range of 3–9 and is suitable for routine monitoring of BPA in bottled drinking water, for regulatory purposes. Furthermore, this method should also allow easy expansion to water quality records for BPA in different water samples and also related compounds like octyl and nonyl phenol as well as bisphenol S and bisphenol F in water.