Development of a chemiluminescence sensor based on molecular imprinting technology for the determination of trace monocrotophos in vegetables

Abstract

In this study, a new sensor of molecularly imprinted solid-phase extraction coupled with flow-injection chemiluminescence for the detection of monocrotophos was fabricated. The molecularly imprinted polymer was synthesized by the bulk polymerization, using monocrotophos, methacrylic acid, and ethylene glycol dimethacrylate as the template molecule, functional monomer, and cross-linker, respectively. The adsorption and recognition ability of the imprinted polymer toward monocrotophos was investigated. Factors influencing preconcentration of the analytes and sensitivity of the method were optimized. Under the optimal conditions, the chemiluminescence intensity was linearly proportional to the concentration of monocrotophos range from 0.0023 to 10 mg/L, and the limit of detection of the method was 0.001 mg/L. Rape (Brassica napus) and pakchoi (Brassica rapa subsp. chinensis) samples spiked with monocrotophos at three levels were analyzed by the developed method with recoveries between 89.3% and 105.9%. This method was successfully applied to the determination of monocrotophos in spinach samples, and the results were verified by gas chromatography method. K E Y W O R D Schemiluminescence, molecular imprinting, monocrotophos, solid-phase extraction