Abstract: A selective, sensitive, rapid and reliable method based on molecularly imprinted polymers (MIPs) with dual templates to determine total content of parabens in cosmetics was developed. With methylparaben (MP) and propylparaben (PP) as dual-templates, methacrylic acid (MAA) as a functional monomer and tripropylene glycol diacrylate (TPGDA) as a cross-linker, MIPs film on a glassy carbon electrode was constructed as parabens sensor. At oxidation potential of 0.94 V (vs.SCE), the peak currents on the MIPs sensor were proportional to the concentration of parabens with square wave voltammetry. As the ratio of MP to PP in the MIPs was 1:1.25, the regression equations for four parabens were almost the same. The linear range was 20-100 μM for MP and EP, 5-100 μM for PP, and 5-80 μM for BP, with detection limit of 0.4 μM for MP and EP, 0.2 μM for the others. The total content of parabens could be calculated according to the average of these four regress equations. At least ten times of structural analogs such as p-hydroxybenzoic acid, p-aminobenzoic acid and phenol would not interfere with the determination of parabens. Nonanalogous coexistences such as vitamin C had no response on the sensor at all. Rapid response of the MIPs sensor was obtained within 1min. MIPs sensor had been used to determine total content of parabens in cosmetic samples with recoveries between 98.7% and 101.8%. It reveals that the MIPs sensor with multi-templates has a potential to determine the total content of a group of homologous compounds
Template and target information: methylparaben, MP, propylparaben, PP, dual templates, mixed templates
Author keywords: Dual-templates, Molecularly imprinted polymers, Parabens, Square wave voltammetry

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