Synthesis of dummy-template molecularly imprinted polymers as solid-phase extraction adsorbents for N-nitrosamines in meat products

In this study, the dummy template molecularly imprinted polymers were firstly prepared by precipitation polymerization method using benzhydrol, 5-nonanol and N-formylpyrrolidine as template molecules and methacrylic acid as functional monomer. The obtained polymers were characterized and showed spherical particles with loose and porous surface. The dynamic and static adsorption experiments indicated that the polymers exhibited large adsorption capacity, high adsorption efficiency and specific recognition ability towards N-nitrosamines. The parameters of solid phase extraction process were carefully optimized. Under the optimized conditions, the solid phase extraction process based on dummy molecularly imprinted polymers coupled with high performance liquid chromatography-tandem mass spectrometry for analyzing N-nitrosamine in various processed meat products was established. This proposed method showed good linearity (R2 >= 0.9985), and the limits of detection and the limits of quantification were in the range of 0.03-0.65 ng/g and 0.1-1.95 ng/g, respectively. With three spiked concentrations (5, 10, and 20 ng/g), satisfactory recoveries (61.0-105.2 %) were also obtained with relative standard deviations between 1.20 and 9.76 %. Those results demonstrated that the method for N-nitrosamine possessed the advantages of high selectivity, good reproducibility and high sensitivity, providing great convenient method for enriching and detecting N-nitrosamine in complex food matrix.