Optimized Stir Bar Sorptive Extraction Based on Self-Magnetic Nanocomposite Monolithic Kit for Determining Bisphenol A in Bottled Mineral Water and Bottled Milk Samples

The current study describes a simple method to monitor bisphenol A (BPA) quantitatively through stir bar sorptive extraction (SBSE) coupled with high-performance liquid chromatography-ultraviolet (HPLC-UV) spectroscopy. The analyte was concentrated by SBSE based on self-magnetic nanocomposite monolithic (SMNM) kit. An experimental design based on the central composite design (CCD) was used to optimize factors affecting SBSE extraction. Limit of detection (LOD) of the BPA was 0.02 μg l-1 and 0.38 μg l-1 for bottled mineral water and bottled milk samples, whereas relative standard deviations (RSDs%) did not exceed 8.49% and 10.21 % for interday and intraday precisions, respectively. Interday and intraday precisions (n = 3) were obtained by extracting BPA at the concentration level of 0.10 μg l-1 for bottled mineral water and 0.50 μg l-1 for bottled milk sample. The calibration curve of BPA showed good linearity for bottled mineral water and bottled milk samples such that the coefficients of determination (R2) were obtained to be 0.9976 and 0.9960, respectively. The proposed method was effectively used to analyze BPA in bottled mineral water and bottled milk samples.