Preparation and application of tebuconazole molecularly imprinted polymer for detection of pesticide residues in tobacco leaves

In this paper, computer simulation technology was used to design the pre-polymerization system of Tebuconazole Molecularly Imprinted Polymer (TBZ-MIPs). The simulation results illustrated that the best functional monomer was MAA, the polymerization solvent was acetonitrile, and the ratio of TBZ to MAA was 1:3. Thermodynamic analysis showed that the self-assembly process of TBZ-MAA was a non-spontaneous endothermic reaction, and the appropriate pre-polymerization temperature was 30 ℃. Based on the computer simulation results, the TBZ-MIPs nanospheres were prepared by precipitation polymerization with TBZ as template molecule, MAA as functional monomer, EGDMA as crosslinking agent, AIBN as initiator, and acetonitrile as solvent. The nanospheres had a uniform particle size, and the average diameter was 188.83 nm. Adsorption experiments indicated that the TBZ-MIPs had good specific adsorption capacity for TBZ and its structural analogs, the maximum dynamic adsorption capacity could reach to 1.8 mg/g in 60 min. Further, the TBZ-MIPs nanospheres were used as the filler of the solid phase extraction tube to pretreat the tobacco samples, and the method of TBZ-MISPE-UHPLC-MS/MS was established to detect trace tebuconazole, myclobutanil and triadimenol in tobacco leaves simultaneously. Their average recovery rates and RSD were 70.5% ~ 110.17%, and 0.78% ~ 12.71% (n = 3) respectively, which realized trace detection of triazole fungicides in tobacco leaves.