巯基乙胺修饰电极法测定植物体内超氧阴离子自由基  

Determination of Superoxide Anion Radical in Plant by Mercaptoethylamine Modified Electrode

作　　者：王燕[1] 陈蓁蓁[1] 

机构地区：[1]山东师范大学化学化工与材料科学学院,济南250014

出　　处：《分析化学》2008年第11期1505-1509,共5页Chinese Journal of Analytical Chemistry

基　　金：山东省自然科学基金(No.Y2006B28)资助项目

摘　　要：盐酸羟胺与超氧阴离子自由基反应生成NO2^-,通过检测NO2^-的生成量,可间接测定超氧阴离子自由基。基于上述原理,建立了一种用巯基乙胺自组装修饰金电极测定生物体系中超氧阴离子自由基的新方法。实验结果表明,在pH4.8的HAc-NaAc缓冲溶液中,修饰电极对NO2^-的氧化具有良好的电催化作用,差分脉冲溶出伏安法测定其氧化峰电流与NO2^-的浓度在5.0×10^-8-1.0×10^-4mol/L范围内呈线性关系,其线性回归方程为ipa（μA）=3.726C（μmol/L）＋0.0257,相关系数为0.9983;检出限为1.0×10^-8mol/L。该法用于玉米幼苗和叶片中超氧阴离子自由基产生速率的测定,结果令人满意。Hydroxylammonium can react with superoxide anion radical to form nitrite ion. Indirect determination of superoxide anion radical can be realized by detecting NO2^-. Based on this principle, an electrochemical method was proposed for the determination of superoxide anion radical in the plant by the determination of NO2^- with self-assembled mereaptoethylamine modified gold electrode. The modified electrode showed an excellent electroeatalytical effect on oxidation of NO2^-. In pH 4.8 HAc-NaAe buffer solution, the anodic peak current had a linear relationship with NO2^- concentration in the range of 5.0 ×10^-8- 1.0 ×10^-4 mol/L with a correlation coefficient of 0. 9983 by differential pulse stripping vohammetry. The linear equation was ipa（μA） =3.726C（μmol/L） ＋0. 0257, the detection limit was 1.0 ×10^-8 mol/L. The proposed method was applied to determine the generation rate of superoxide anion radical in corn seedling and leaves with satisfactory results.

关 键 词：超氧阴离子自由基 化学修饰电极 巯基乙胺 差分脉冲溶出伏安法 

分 类 号：Q946[生物学—植物学]