碳糊电极阳极吸附伏安法测定洛美沙星

Determination of lomefloxacin by anodic adsorptive voltammetry at a carbon paste electrode

报道了碳糊电极阳极吸附伏安法测定洛美沙星的新方法。在0.096mol L的KHP NaOH(pH5.4)缓冲液中,用碳糊电极为工作电极,在0.3V(vs.SCE)富集一定时间,然后从0.3～1 3V以300mV s扫速线性扫描,记录其在1 02V的二次导数阳极溶出峰。溶出峰电流与洛美沙星浓度在8.0×10-9～8.0×10-8mol L(富集90s)和8.0×10-8～8.0×10-7mol L(富集30s)范围内呈良好的线性关系,相关系数分别为0.9844和0.9967,检出限为9.0×10-10mol L(S N=3)。探讨了洛美沙星在碳糊电极上的伏安性质和电极反应机理,并且成功地应用于人体尿液中洛美沙星的测定,结果与紫外光度法基本吻合。

A new anodic adsorptive voltammetric method was developed for the determination of trace amount of lomefloxacin at a carbon paste electrode (CPE). The lomefloxacin was adsorbed on the surface of CPE in KHP-NaOH buffer solution (pH 5.4), yielding one oxidation peak at 1.02 V(vs.SCE). The relationship between the peak current and lomefloxacin concentration is linear in the ranges of 8.0×10^(-9)～8.0×10^(-8) mol/L(90 s accumulation)and 8.0×10^(-8)～8.0×10^(-7) mol/L(30 s accumulation). The correlation coefficients are 0.9844 and 0.9967, respectively. The detection limit was 9.0×10^(-10) mol/L (S/N=3) for 90 s accumulation. The electrode reaction mechanism of lomefloxacin was investigated. The proposed method was applied to the determination of trace lomefloxacin in the urine samples.