Coiled molecularly imprinted polymer layer open-tubular capillary tube for detection of parabens in personal care and cosmetic products.

Personal care and cosmetic products (PCPs) are the primary exposure pathway of humans to parabens and their safety has become a public concern. However, sample pretreatment of PCPs is a great challenge due to their complexities and diversity. In this study, epoxide modified molecularly imprinted polymers (MIPs) were synthesized using ethylparaben as a template, methacrylic acid and isobutyl vinyl ether as co-monomers and glycidilmethacrylate as a post-modified monomer. MIP layer open-tubular tubes were prepared by modifying branched polyethylenimine and then grafting MIPs onto the inner surface of Teflon capillary tubes. The tube was coiled to effectively increase mass transfer and coupled to an HPLC-UV system for parabens detection in PCPs. Matrix interference was significantly decreased while efficient enrichment and recoveries were obtained. Under optimized conditions, the linear range for parabens detection was 0.5–600 ng mL−1 with detection limits of 0.2 to 0.3 ng mL−1. The system was used to study the contents of parabens in popular PCPs. The concentrations of parabens in 108 PCPs ranged from <0.5 ng g−1 to 2856 μg g−1 with geometric mean of 250.3 μg g−1. Almost all of the products contained at least one kind of parabens; methyl paraben (geometric mean: 182.9 μg g−1) and n-propyl paraben (geometric mean: 42.5 μg g−1) were the predominant compounds had been found in the samples. This method could be useful for human exposure assessment towards parabens.