光谱法研究异丙甲草胺及其S-对映体与脲酶的相互作用机制  

The Reaction Mechanism of Metolachlor and S-Isomer with Urease

作　　者：刘惠君[1] 刘维屏[1] 陈爱平[1] 杨炜春[1] 

机构地区：[1]浙江大学环境科学研究所,浙江杭州310027

出　　处：《光谱学与光谱分析》2004年第2期166-168,共3页Spectroscopy and Spectral Analysis

基　　金：浙江省教委基金项目 ( 2 0 0 0 43 6);浙江省分析测试基金 ( 0 3 12 0 )项目资助

摘　　要：应用紫外差光谱和荧光光谱法研究了水溶液中酰胺类除草剂异丙甲草胺及其S 异构体与脲酶分子间的相互作用。结果表明 ,随着除草剂浓度的增加 (0 0～ 1 6 μmol·L-1 ) ,脲酶的紫外吸收光谱发生红移 ,吸收强度减弱。除草剂对脲酶的荧光均有猝灭作用 ,且静态猝灭是引起脲酶荧光猝灭的主要原因。从荧光猝灭结果求出了除草剂和脲酶的结合常数及结合位点数。异丙甲草胺 :K =1 4 9× 1 0 3 L·mol-1 ,n =0 84 ;S 异丙甲草胺 :K =2 2 2× 1 0 3 L·mol-1 ,n =0 89。The binding of metolachlor and S Isomer to urease in aqueous solution was studied using UV difference spectrum and fluorescence spectrum. According to the results of the UV difference spectrum curve, the UV difference adsorption Δ A changed rapidly when herbicide concentration increased from 0 0 to 1 6 μmol·L -1 . UV difference spectra were red shifted and absorb peaks became lower. It was shown that herbicide can quench the urease fluorescence mainly through a static quenching procedure. The binding constant K and the number of binding site n were calculated according to the fluorescence quenching results. For metolachlor, K =1 49×10 3 L·mol -1 and n was 0 84; for S isomer, K =2 22×10 3 L·mol -1 and n was 0 89.

关 键 词：光谱法 异丙甲草胺 S-对映体 脲酶 相互作用 酰胺类除草剂 荧光猝灭 键合常数 结合位点数 

分 类 号：S482.4[农业科学—农药学]