Synthesis And Application Of Fragment-Imprinted Microspheres Of Sulfonamides In Food Analysis

In this paper, fragment-imprinted microspheres (FIMs) were prepared by suspension polymerization. FIMs were synthesized by using fragment imprinting technology. The optimum conditions were obtained by an orthogonal experiment. The particle size distribution of the FIMs was investigated by a particle size analyzer. The morphological structure of the FIMs was assessed by scanning electron microscopy. The equilibrium adsorption and selectivity of FIMs were evaluated. A method for the simultaneous determination of five sulfonamides by fragment imprinted-solid phase extraction (FI-SPE) coupled with HPLC from milk samples was developed. The following contents are studied:1.2,6-Dichloropyrimidine instead of sulfonamides was used as the template molecule, a-methacrylic acid and styrene were the mixed functional monomers, ethylene dimethacrylate was the crosslinking agent, and azodiisobutyronitrile was the initiator. Based on orthogonal intuitive analysis, the following optimum synthesis conditions were obtained:80℃,1:4:20molar ratio of template, monomer, and crosslinker;1:6molar ratios of ST to MAA; and1%initiator dosage. The absorption amount of sulfadiazine, sulfa-5-methylpyrimidine, sulfamethazine, sulfamethoxazole, and sulfamonomethoxine by FIMs were6mg g-1,9.63mg g-1,6.31mg g-1,10.25mg g-1and14.96mg g-1, respectively. While the NTMs were1.31mg g-1,2.78mg g-1,1.00mg g-1,3.81mg g-1and2.89mg g-1, respectively. The polymer microspheres were loaded into the solid phase extraction cartridge. Solid phase extraction conditions:perchloric acid (pH=2) was the loading solvent, distilled water was the washing solvent, methanol was the sample elution solvent. The method of the deternination of sulfonamides in milk samples were has been developed used FI-SPE. The linear range; of the method; was0.10～150μg mL-1; and the limit; of detection; was0.015μg mL-1. The recoveries for sulfamethoxazole extractions were found to be89.1%,92.8%,90.9%with relative standard deviations of1.28%,1.92%,2.31%at levels of1μg ml/1,5μg mL-1,10μg mL-1, respectively, indicating the feasibility of the prepared FIMs for sulfonamide extraction.2.4-Sulfa-6-Chloropyrimidine instead of sulfonamides was used as the template molecule, a-methylacrylic acid and styrene were the mixed functional monomers, dvinylbenzene was the crosslinker, and azobisisobutyronitrile was the initiator. The optimum conditions were obtained by an orthogonal experiment. Based on orthogonal intuitive analysis, the following optimum synthesis conditions were obtained:80℃,1:60:150molar ratio of template, monomer, and crosslinker;1:1molar ratio of styrene to a-methylacrylic acid; and1%initiator dosage. The maximum adsorption was obtained under the optimum conditions. The absorption amount of sulfadiazine, sulfa-5-methylpyrimidine, sulfamethazine, sulfamethoxazole, and sulfamonomethoxine by FEVIs were6.64mg g-1,8.95mg g-1,6.32mg g-1,9.31mg g-1and10.89mg g-1, respectively. Whereas the absorption by NTMs were4.85mg g-1,5.61mg g-1,2.68mg g-1,5.67mg g-1and6.39mg g-1, respectively. The polymer microspheres were loaded into the solid phase extraction cartridge. The method of the deternination of sulfonamides in milk samples were has been developed used FI-SPE. The linear ranges of the method were0.05～100μg ml/1, and the limit of detection was0.013μg ml/-1. The recoveries for sulfamethoxazole extractions were found to be90.8%,95.9%,91.3%with relative standard deviations of2.46%,1.09%,2.17%at levels of1μg ml/1,5μg ml/1,10μg ml/1, respectively, indicating the feasibility of the prepared FIMs for sulfonamide extraction.