Synthesis And Characterization Of Nitenpyram Molecularly Imprinted Polymers

Molecularly imprinted polymers (MIPs) are new synthetic materials with specific affinity and highselectivity for a particular target molecule. After pre-polymerization between the template molecule and thepolymerizable functional monomers, adding polymerization initiators and crosslinkers into the pre-polymerization solutions to produce the polymer matrix, thus obtaining the molecularly imprinted polymersby using physical or chemical methods to elute the template molecules from the polymer matrix. There arevacant imprinted sites that are complementary in shape, size and functionalities to those of the template.Molecularly imprinted polymers have many advantages such as strong resistance to acid environment, hightemperature, high pressure, ease of synthesis and be reused many times. What’s more, they have beenwidely applicated in the field of solid-phase extraction wide, sensors, membrane technology and enzymecatalysis application.In this thesis, molecularly imprinted polymers of Nitenpyram are synthesized successfully, and havebeen applicated as solid-phase extraction filters and stir bar sorptive extraction coatings in the enrichmentand analysis of Nitenpyram in environmental samples. The main component of the experimental studyincludes two parts：(1) Nitenpyram molecularly imprinted polymers were prepared successfully by using nitenpyram astemplate molecule, methacrylic acid (MAA) as functional monomer and ethylene glycol dimethaerylate(EGDMA) as crosslinker in acetonitrile. Optimization of the polymerization conditions, the staticequilibrium adsorption experiment results show that there is a homogeneous binding site to nitenpyram inthe nitenpyram molecularly imprinted polymers, and the apparent maximum amount is1616μg/g. Theselectivity of MIPs was investigated by selectivity experiment, the results indicated that the nitenpyrammolecularly imprinted polymers showed good specificity recognition ability. Using molecularly imprintedpolymers as solid phase extraction fillters to study the selective extraction properties of the polymers, andexploring the application feasibility for the molecularly imprinted polymers (MIPs) in separation andenrichment of nitenpyram.(2) A new stir bar sorptive extraction (SBSE) coating based on molecularly imprinted polymer (MIP) with nitenpyram as template molecule was prepared. The influences of the preparation condition on theextraction performance of MIP-SBSE were investigated. The selective extraction performance ofMIP-SBSE was explored to extracting nitenpyram and other neonicotinoid pesticides in environmentalwater samples. To achieve optimally selective extraction performance for nitenpyram, several parameters,including adsorption and desorption time,ionic strength and pH value in sample matrix were investigated.The results showed that under the optimized experimental conditions, the MIP-SBSE of nitenpyram hasparticular selectivity and higher enrichment, the averages of the sample standard addition recovery rateswere85.3%～112.4%in actual water samples.This study provides a feasible method to the enrichment and separation of Nitenpyram inenvironmental samples, simplifies tedious steps of the traditional methods to enrich and separate traceNitenpyram in environmental samples, largely reduces the matrix interferences in environmental samplesfor the determination of trace components.