电活化玻碳电极差分脉冲溶出伏安法测定磺胺嘧啶

采用线性循环溶出伏安法和差分脉冲溶出伏安法对磺胺嘧啶在电活化玻碳电极上的电化学行为进行了研究。玻碳电极在PBS溶液中(pH 7.0),用恒电位法在1.7 V阳极氧化400 s,在B-R缓冲溶液中,磺胺嘧啶在1.02V(vs.Ag/AgCl)处有一良好的氧化峰,在0.02～0.25 V/s范围内,其氧化峰电流与扫描速率呈良好线性关系,表明电极过程为受吸附控制的不可逆过程。差分脉冲溶出伏安法的氧化峰电流(Ipa)与磺胺嘧啶浓度1×10-6～1×10-4mol/L范围内呈良好的线性关系(r=0.9977),检出限为8.7×10-7mol/L(S/N=3)。方法已用于分析磺胺嘧啶片剂的分析。

Determination of sulfadiazine by differential pulse s stripping voltammetry with an electro-activated glassy carbon electrode

Electrochemical behavior of sulfadiazine(SD) at an electro-activated glassy carbon electrode(EGCE) was studied by linear sweep stripping voltammetry(LSSV) and differential pulse stripping voltammetry(DPSV).The glassy carbon electrode(GCE) was activated in pH 7.0 phosphate buffer solution(PBS) for 400 s by potentiostatic method at +1.7 V.In pH 4.5 Britton-Robinson buffer solution(B-R),a well defined oxidative peak of SD was observed at 1.02 V(vs.Ag/AgCl) with the activated electrode,The anodic peak current increased linearly with scan rate from 0.02 to 0.25 V/s,revealing that the reaction was a surface-controlled process.Experimental parameters were optimized and the correlation between peak current(Ipa) and concentration was studied by differential pulse stripping voltammetry.Under the optimal conditions,the linear range for the detection of SD was 1×10-6 to 1×10-4 mol/L with a correlation coefficient of 0.9977,and the detection limit was 8.7×10-7 mol/L(S/N=3).The activated glassy carbon electrode is easy to be prepared with good reproducibility.