Synthesis and Characterization of Molecularly Imprinted Polymers for the Selective Extraction of Carbamazepine and Analogs from Human Urine Samples

Two molecularly imprinted polymers (MIPs) were synthesized according to a previous work from our group dealing with the extraction of carbamazepine from environmental water. The potential of these MIPs, which differ in the nature of the monomer used for their synthesis, to selectively extract the drugs carbamazepine and oxcarbazepine and the metabolite 10,11-epoxycarbamazepine was first studied in spiked pure water, and high selectivity was obtained with both MIPs for the three target molecules in this pure medium. This selectivity was maintained when applying one of the MIPs to urine samples. Indeed, extraction recoveries were higher than 82% on the MIP and lower than 20% on the corresponding non-imprinted polymer used as a control. The repeatability of the extraction procedure applied to urine was also demonstrated, with relative standard deviation (RSD) below 20% for extraction recoveries of the three targets at a spiking level of 20ng L-1. Limits of quantification between 1 and 7ng L-1 were determined for urine samples using the MIP as extraction sorbent combined with LC-MS analysis. The potential of the MIP was compared to that of the Oasis HLB sorbent. This study shows that the MIP constitutes a powerful tool for avoiding matrix effects encountered in the quantification of the target molecules in urine samples extracted on Oasis HLB.