Design and implementation of an imprinted material for the extraction of the endocrine disruptor bisphenol A from milk

• An imprinted polymer for bisphenol A was designed with hydroquinone as template.
• MIP-SPE method for bisphenol A in milk was developed and validated.
• Testing milk samples, bisphenol A was identified in one at a level of 176 μg kg−1.
• BPA self-association effects were examined with crystallography.
• Pre-polymerization interactions were studied using molecular dynamics simulations.

This paper describes the determination of bisphenol A (BPA) in milk samples, using a novel molecularly imprinted polymer. The imprinted polymer was developed using a rational design approach, and pre-polymerization interactions were investigated using molecular dynamics simulations and X-ray crystallography. A hydroquinone-imprinted polymer was used for solid phase extraction (SPE) clean-up of samples. BPA was quantified by high performance liquid chromatography (HPLC) and fluorescence (FLD) detection. Following validation, the method described was capable of determining bisphenol A in milk down to a limit of detection of 1.32 μg kg−1. The method was applied to a survey (n = 27) of commercial milk products; BPA was detected in one of the samples, at a level of 176 μg kg−1. Test results were confirmed by a parallel UHPLC–MS/MS analytical method. This demonstrates the utility of the hydroquinone-imprinted polymer for application to selective sample clean-up and analysis of bisphenol A in milk, avoiding possible detrimental affects associated with template bleeding and without the need for expensive or difficult-to-obtain template.