碳糊电极阳极吸附伏安法测定卡托普利

Anodic Adsorptive Voltammetric Determination of Captopril at a Carbon Paste Electrode

在0.40 mol/L的HAc-NaAc(pH=4.8)缓冲溶液中,卡托普利(Captopril,CPT)在碳糊电极(CPE)上有一灵敏的吸附氧化峰,峰电位为0.23 V(vs.SCE)。该氧化峰的二阶导数峰电流与卡托普利的浓度在2.0×10-8～1.0×10-6mol/L(富集90 s)范围内呈良好的线性关系,相关系数为0.9966,检出限为8.0×10-9mol/L,并成功应用于卡托普利片含量的测定。探讨了卡托普利在碳糊电极上的伏安性质和电极反应机理。

A highly selective and rapid anodic adsorptive voltammetric method has been developed for the determination of trace amount of captopril at a carbon paste electrode（CPE）in the current paper.Captopril is adsorbed on the surface of the CPE in 0.40 mol/L HAc-NaAc buffer solution（pH=4.8）,yielding one oxidation peak at 0.23 V（vs.SCE）.The relationship between the peak current and captopril concentration is linear in the range of 2.0×10-8~1.0×10-6 mol/L with the correlation coefficient of 0.9966.The detection limit is 8.0×10-9 mol/L（S/N=3） for 90 s acummulation.The proposed method was applied to the direct determination of captopril in the captopril tablet with satisfactory results and the electrode reaction mechanism of captopril was investigated.