摘要
本文利用吡虫啉(Imidacloprid,IMI)在Na2HPO4-NaH2PO4缓冲溶液(PBS,pH=8.0)与1.0×10^-3mol/L十二烷基磺酸钠(SDS)的底液中,能够产生一个灵敏的还原峰,从而建立了一种测定农作物中吡虫啉农药残留的极谱分析新方法。实验于起始电位-0.40V(vs.SCE),以700mV/s扫描,在峰电位-1.10V左右(vs.SCE),吡虫啉浓度分别在2.0×10^-6~2.8×10^-5mol/L和2.8×10^-5~1.24×10^-4mol/L的范围内与其峰电流成线性关系,检出限为1.02×10^-7mol/L。该方法直接用于农作物中吡虫啉残留测定,加标回收率为92.7%~109.2%。用单扫描极谱法研究了检测体系的电化学行为,实验证明极谱波为不可逆还原吸附波。初步探讨了电极反应机理。
A new polarographic method for the determination of imidacloprid(IMI) residues in crops was established. It based on the sensitive reduction peak generated by IMI in Na2HPO4-NaH2PO4(PBS)(pH=8.0) buffer solution and 1.0×10-3 mol/L sodium dodecyl sulfate(SDS). Under optimized condition, the initial potential was-0.40 V(vs.SCE) and the peak potential was about-1.10 V(vs, SCE) by polarography. The peak current is linearly proportional to the concentration of IMI over the range of 2.0×10-6-2.8×10-5 mol/L and 2.80×10-5-1.24×10-4 mol/L, the detection limit is 1.02×10-7 mol/L. The method was used for the detection of the residual content of IMI in crops. The recovery of the samples was 92.7%-109.2%. The electrochemical behavior of the detection system was investigated by single-sweep polarography. The experimental results indicate that the polarographic wave is an irreversibly reduced adsorption wave, and the reaction mechanism of the electrode was discussed.
作者
胥亚庆
陈文
覃凡
XU Ya-qing;CHEN Wen;QIN Fan(College of Materials and Chemistry & Chemical Engineering,Chengdu University of Technology,Chengdu 610059;Mineral Resources Chemistry Key Laboratory of Sichuan Higher Education Institution,Chengdu 610059)
出处
《分析科学学报》
CAS
CSCD
北大核心
2019年第4期438-442,共5页
Journal of Analytical Science
关键词
吡虫啉
极谱法
农药残留
Imidacloprid
Polarography
Pesticide residuce