Determination of bisphenol A in plastic bottle packaging beverage samples using ultrasonic-assisted extraction and flame atomic absorption spectrometry

Abstract

In this work, a simple and versatile ultrasound-assisted extraction (UAE) procedure, which provides high separation efficiency for bisphenol A (BPA), was developed for its indirect determination in beverages in contact with plastic containers by flame atomic absorption spectrometry (FAAS). The method is based on charge transfer reaction, in which BPA reacts with Cu(II) in alkaline tartrate solutions of pH 8.0 to produce Cu(I), which reacts with ion-pairing reagent, Promethazine, being a phenothiazine derivative (PMZ), in the presence of cetyl trimethylammonium bromide (CTAB). For the indirect determination of BPA using FAAS, the change in signal of Cu(II) depending on BPA concentration was investigated in detail. At optimal conditions, the analytical features of the method were obtained as follows; linearity ranges of 1.5-100 µg L-1 for direct aqueous calibration solutions and 3-125 µg L-1 for matrix matched calibration solutions; the limits of detection and quantification of 0.47 and 1.56 µg L-1 ; sensitivity enhancement and pre-concentration factors of 135 and 150, respectively. The method accuracy was validated by repeatability/reproducibility precision studies using standard addition method. As the last, the method was successfully applied for determination of BPA in selected samples. BPA as a food stimulant was detected in ranges of 2.70-3.80 µg L-1 in waters and 3.10-5.40 µg L-1 in milk products while its levels changed in ranges of 6.40-7.70 and 4.30-19.2 µg L-1 in beverages with and without alcohol. These levels were highly lower than the specific migration limit set by European Union.