Determination of Bisphenol a in Water and Milk by Micellar Liquid Chromatography

Polycarbonate plastics (PC) containing bisphenol A (BPA) are used for production of bottles for water, containers for storage of food products, bottles for feeding infants, kitchen utensils, and some components of medical equipment. Trace amounts of BPA have been detected in water and food products kept in PC containers. It has been established that BPA can be liberated from PC containers and migrate into the food products kept in them. Such migration is facilitated by use of detergents for washing such containers. This study was undertaken to establish a simple and rapid method for determination of BPA in powdered milk and mineral water commercially available in PC containers. Residues of BPA in mineral water and milk were preconcentrated by solid-phase extraction and determined by micellar liquid chromatography. The micellar mobile phase was an aqueous solution of 0.2 M sodium dodecyl sulphate (SDS) and 10% 2-propanol. The linearity of the calibration plot was tested by use of water samples containing BPA at concentrations from 0.5 to 100 μg L and 2,2-bis-(4-hydroxyphenyl)-propane-bis(2,3-epoxypropyl) ether (BADGE) at concentrations from 1.0 to 100 μg L. Recovery of BPA and BADGE from water was 92.3 and 84.2%, respectively. Detection limits for BPA and BADGE were 0.3 and 0.6 μg L, respectively, and quantification limits were 1.0 and 2.0 μg L, respectively. The method proposed is characterised by high accuracy and precision.