【摘要】 研究了生理介质中硝普钠(SNP)在玻碳电极(GCE)上的直接电化学行为。结果表明,在电位窗口-0.60~0.30 V(vs.SCE)及0.15 mol/L NaCl水溶液中,SNP的电化学过程呈现出一准可逆的氧化还原过程,△E=110 mV,还原峰电位(Epc)和氧化峰电位(Epa)分别为-0.200 V和-0.090 V。在扫描速度10~1 000 mV/s范围内其还原峰电流和氧化峰电流与扫描速度的平方根(v1/2)呈良好的线性关系,表明SNP在GCE上的伏安行为是一受扩散控制的电化学过程。用循环伏安法(CV)、计时电量法(CC)和计时电流法(CA)测定了SNP在GCE上的电极过程动力学参数如电荷传递系数α,扩散系数D以及表观速度常数Kf。同时运用方波伏安法(SWV)研究了SNP在GCE上的方波伏安行为,发现SNP的还原峰电流与其浓度在2.0×10-5~1.8×10-2mol/L范围内有良好的线性关系,相关系数R=0.9973;检出限为1.0×10-5mol/L。据此,建立了测定SNP含量的直接电化学分析方法,测定结果的相对标准偏差在0.8%~1.4%之间;标准加入回收率在96.3%~100.5%之间。该法简单、快捷、准确,测定结果令人满意。更多还原

【Abstract】 The direct electrochemical behaviors of sodium nitroprusside（SNP） in physiological medium on glassy carbon electrode have been investigated in this paper.Electrochemical results show that SNP electrochemical behaviors exhibit a quasi-reversible!redox process,the reduction and oxidation peak potential(E_pc and E_pa) are-0.200 and-0.090 V,respectively.In the scan rate range of 10¹ 000（mV/s,） the reduction and oxidation peak currents are linear with the square root of the scan rate which showed that electrochemical behavior of SNP on GCE is a diffusion controlled electrochemical process.The electrode kinetic parameters such as charge transfer coefficient α,diffusion coefficient D and apparent reaction rate constant k_f are determined by CV,CC and CA.Electrochemical behaviors of SNP are also studied by SWV in the concentration range of 2.0×10^-51.8×10^-2 mol/L.It was found that the reduction peak currents are linear with SNP concentration with a detection limit of 1.0×10^-5 mol/L.更多还原