Two molecularly imprinted polymers (MIPs) were synthesized, by sol-gel and radical polymerization procedures. These MIPs were evaluated as selective stationary phases for miniaturized solid phase extraction (MISPE) to determine parabens in plasma samples by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Selective cavities of the MIPs, based on molecular recognition (hydrogen bonds), were revealed after removal of the template (benzylparaben). Both MIPs were characterized by scanning electron microscope (SEM) and Fourier-transform infrared spectroscopy (FTIR). MIP prepared by radical process presented higher selective binding capacity for the target parabens than MIP prepared by sol-gel. Several variables that influence MISPE performance, including sample pH, sorbent washing, elution solvent, and elution solvent volume were also evaluated. According to the analytical validation parameters, the MISPE/UHPLC-MS/MS method is suitable for the analysis of parabens in plasma samples. The effectiveness of this method was demonstrated through the analyses of the umbilical plasma samples from postpartum women.
Keywords:
parabens; molecularly imprinted polymer; miniaturized solid phase extraction; UHPLC-MS/MS; plasma samples
