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 is a monomer used in production of several plastic resins in food storage containers. Residue of BPA in plastics can be found in foods filled into the containers. Due to this fact that 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 into the water sample or aqueous phase obtained from milk after its deproteinization with trichloroacetic acid. In both samples, the obtained cloudy solutions were centrifuged and the sedimented phase analyzed by 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. Comparing the results with maximum residue limit established by European Commission showed that BPA content was higher than the permitted level.