Non-hydrolytic Sol-gel Methodology to Prepare a Molecularly Imprinted, Organic-silica Hybrid-based Stir Bar for Recognition of Sulfonylurea Herbicides  

作　　者：司汴京 周杰 

机构地区：[1]College of Chemistry and Material Science, Shandong Agricultural University, Taian, Shandong 271018, China

出　　处：《Chinese Journal of Chemistry》2011年第11期2487-2494,共8页中国化学（英文版）

基　　金：Project supported by National High-tech R ＆ D Program （863 program, No. 2007AA 10Z432） and the National Natural Science Foundation of China （No. 30871756 and 21175083）.

摘　　要：Based on a molecularly imprinted organic-silica hybrid-based stir bar, a pre-treatment methodology was devel- oped for enrichment of nicosulfuron in aqueous samples. The molecularly imprinted organic-silica hybrid-based coating on the outer surface of a glass stir bar was prepared by in-situ polymerization using nicosulfuron as a template molecule, a-methacrylic acid as a functional monomer, methacryloxypropytrimethoxysilane as a cross-linker in the mixture of acetonitrile and trichloromethane （V/V, 7.5 ： 1）. To achieve the selective extraction of the target analyte from aqueous samples, several main parameters, including extraction time, pH value and contents of inor- ganic salt in the sample matrix were investigated. Evidence was also presented by the scanning electronic micro- scopic images of the imprinted and non-imprinted stir bars. Then, the extraction efficiency of the stir bar was tested with separate experiments and competitive sorption experiments. These results showed that using six sulfonylureas as substrates the molecularly imprinted organic-silica hybrid-based stir bar gave high selectivity for the template, nicosulfuron compared to the non-imprinted organic-silica hybrid-based stir bar. This sorption extraction was cou- pled to liquid chromatography ultraviolet detection allowing the determination of nicosulfuron from tap water. The method showed good recoveries and precision, 96.0% （RSD 2.7%, n=3） for tap water spiked with 0.125 nmol （25.00 mL sample）, suggesting that the stir bar can be successfully applied to the pre-concentration of nicosulfuron in real aqueous samples.Based on a molecularly imprinted organic-silica hybrid-based stir bar, a pre-treatment methodology was devel- oped for enrichment of nicosulfuron in aqueous samples. The molecularly imprinted organic-silica hybrid-based coating on the outer surface of a glass stir bar was prepared by in-situ polymerization using nicosulfuron as a template molecule, a-methacrylic acid as a functional monomer, methacryloxypropytrimethoxysilane as a cross-linker in the mixture of acetonitrile and trichloromethane （V/V, 7.5 ： 1）. To achieve the selective extraction of the target analyte from aqueous samples, several main parameters, including extraction time, pH value and contents of inor- ganic salt in the sample matrix were investigated. Evidence was also presented by the scanning electronic micro- scopic images of the imprinted and non-imprinted stir bars. Then, the extraction efficiency of the stir bar was tested with separate experiments and competitive sorption experiments. These results showed that using six sulfonylureas as substrates the molecularly imprinted organic-silica hybrid-based stir bar gave high selectivity for the template, nicosulfuron compared to the non-imprinted organic-silica hybrid-based stir bar. This sorption extraction was cou- pled to liquid chromatography ultraviolet detection allowing the determination of nicosulfuron from tap water. The method showed good recoveries and precision, 96.0% （RSD 2.7%, n=3） for tap water spiked with 0.125 nmol （25.00 mL sample）, suggesting that the stir bar can be successfully applied to the pre-concentration of nicosulfuron in real aqueous samples.

关 键 词：stir bar sorption extraction molecularly imprinted sol-gel coating sulfonylurea herbicide NICOSULFURON 

分 类 号：O641.3[理学—物理化学] S482.44[理学—化学]