Determination of Bisphenol A in Packed Milk and Mineral Water Samples Marketed in Tabriz (Iran) in 2020 Using High-performance Liquid Chromatography-ultraviolet Detector

Bisphenol A (BPA) is a monomer used to produce several plastic resins in food storage containers. Residual BPA in plastics can be found in filled foods in containers. Because BPA is an endocrine disruptor, its dietary exposure must be estimated. In this method, the analyte was extracted using a dispersive liquid-liquid microextraction procedure from water and milk samples. For this purpose, a mixture of acetone and chloroform (142 μl) was dispersed in the water sample or in the aqueous phase obtained from milk after its deproteinization with trichloroacetic acid. The obtained cloudy solutions were centrifuged in both samples and the sedimentation phase was analyzed by a high-performance liquid chromatography-ultraviolet detector. Analytical features of the method consist of limits of detection (0.44 ng ml-1 in water and 0.51 ng ml-1 in milk samples) and quantification (1.47 ng ml-1 in water and 1.72 ng ml-1 in milk samples), linearity (r2 = 0.992), precision (RSD ≤ 11.1%), and accuracy (RSD ≤ 3%) were studied under final conditions. The results showed that the obtained results are acceptable. Different milk and water samples were analyzed using the developed method, and BPA was found in several samples in the ranges of 11.2-32.6 and 9.6-23.5 ng ml-1 in milk and water samples, respectively. Comparison of the results with the maximum residue limit established by the European Commission showed that the BPA content exceeded the authorized content. Abbreviations: BPA, Bisphenol A; DLLME, Dispersive liquid-liquid microextraction; RSD, Relative standard deviation; HPLC, High performance liquid chromatography; LPME, Liquid phase microextraction; LOD, limit of detection; LOQ, limit of quantification