Molecularly imprinted polymer for solid phase extraction of nicotinamide in pork liver samples

Nicotinamide (NAM) is often added in fortified infant and various food products to ensure an adequate consumption of vitamin. Thus, a proper monitoring of NAM content in foods can be important. In this study, a selective molecularly imprinted polymer as sorbent for solid phase extraction of NAM in animal sources was successfully developed. The molecularly imprinted polymer was synthesized by bulk polymerization technique. The performances of this polymer as sorbent were investigated in NAM standard solutions. One hundred milligrams of polymer was able to retain up to 244 μg of NAM with recovery >80% when chloroform was used as loading and washing solvent and ethanol as eluting solvent. Other solvent mixtures were also tested. The optimal molecularly imprinted solid phase extraction protocol was defined and used for the clean-up of NAM in pork liver samples. Moreover, the performances of the imprinted polymer were compared with that of nonimprinted polymer and with conventional reversed-phase C18 performances. Pork liver samples spiked with 49 μg mL−1 gave a good percentage of recovery of 87%, with relative standard deviation of 8% for imprinted polymer, whereas only 12% of recovery for nonimprinted polymer and 14% of recovery for reversed-phase C18 sorbent were found