摘要
在裸玻碳电极基底上先利用氨基重氮化化学反应接枝修饰谷氨酰胺,再用电聚合法制备了一种聚氨基酸/含铒杂金属氰桥配位聚合物复合修饰电极(Poly(homocystine)/Er(Ⅲ)-Fe(Ⅲ)-WO_(4)^(2-)CyHMCPs/GCE)。以此修饰电极为工作电极,用预电解伏安法研究了香兰素的电催化氧化反应的伏安行为,证明香兰素具有的苯甲醛基和酚羟基两个电活性位点均能通过电催化氧化而产生伏安峰,而且这两个峰电位比较相近,测定时易产生相互间干扰。但是,若采用预电解伏安法的原理,以优化的预电解电位及预电解时间参数条件下进行示差脉冲伏安法测定时,即可完全消除其吸附氧化前波的干扰。此时,测得主氧化峰电位值与pH值的变化规律完全符合2e^(-)/1H^(+)转移机理预期;香兰素的示差脉冲峰电流值与其浓度在0.5~30μmol/L区间内存在良好的线性关系,线性回归方程分别为I_(p)(μA)=-0.0535+0.2511C_(Va)(μmol/L),R^(2)=0.9984,检测限(LOD,S/N=3)为0.054μmol/L,说明此修饰电极能完全适用于电化学法定量测定香兰素含量。
A poly(homocystine)/Er(Ⅲ)-Fe(Ⅲ)-WO_(4)^(2-) CyHMCPs/GCE composite modified electrode was prepared on a bare glassy carbon electrode base by grafting the glutamine with an amino diazotization chemical reaction followed by an electro-polymerization method.The voltammetric behavior of the electrocatalytic oxidation of vanillin was studied by pre-galvanolysis voltammetry using this modified electrode as the working electrode,and it was demonstrated that both benzaldehyde group and phenolic hydroxyl group of vanillin had two electroactive sites that can generate voltammetric peaks by electrocatalytic oxidation,and the potentials of these two peaks were relatively close to each other,which can easily interfere with each other during the determination.However,if the principle of pre-electrolytic voltammetry was adopted,the interference of the adsorption and oxidation pre-waves can be completely eliminated when the differential pulse voltammetry was performed under the optimized pre-electrolytic potential and pre-electrolytic time parameters.The linear regression equation was I_(p)(μA)=-0.0535+0.2511C_(Va)(μmol/L),R^(2)=0.9984,and the detection limit(LOD,S/N=3)was 0.054μmol/L,indicating that this modified electrode was fully applicable to the quantitative determination of vanillin content by electrochemical method.
作者
朱永玺
马永钧
ZHU Yong-xi;MA Yong-jun(College of Chemistry&Chemical Engineering,Northwest Normal University,Gansu Lanzhou 730070,China)
出处
《广州化工》
CAS
2022年第9期84-86,113,共4页
GuangZhou Chemical Industry
基金
国家自然科学基金地区基金项目(№:21862019)。
关键词
复合修饰电极
杂金属氰桥配位聚合物
预电解伏安法
香兰素
composite modified electrode
cyano-bridged heterometallic coordination polymer
pre-galvanolysis voltammetry
vanillin
