克林沙星的吸附伏安特性及其应用

在0．2mol·L^-1KH2PO4-K2HPO4（pH6．80）底液中，克林沙星（CF）在汞电极上有一线性扫描还原峰，峰电位Eρ=-1．46V（vs．Ag／AgCl），该峰说明汞电极对克林沙星具有明显的吸附性。测得CF在汞电极上的饱和吸附量Гs=4．82×10^-11mol．cm^-2，每个CF分子所占电极面积为2．64nm^2，CF在汞电极上的吸附符合Langmuir吸附等温式。测得吸附系数β=1．06×10^6，25℃时的吸附自由能△G^θ=-32．13kJ·mol^-1，电极反应电子数n=2，不可逆体系动力学参量αnα=1．44，表面电极反应速率常量ks=0．26s^-1。建立了吸附溶出伏安法测定CF的最佳条件，方法的检出限为2．0×10^-8mol．L^-1。

Adsorptive Voltammetric Behavior of Sparfloxacin and Its Application

In a supporting electrolyte of 0.2 mol · L^ -1KH2PO4-K2 HPO4 （pH 6.80）, a reduction peak of clinafloxaein （CF） with a potential of --1.46 V （vs. Ag/AgCl） and adsorptive characteristics was observed by linear scanning voltammetry at Hg electrode. The obtained results showed that the saturated adsorption amount of CF on Hg electrode was 4.82 ×10^-11 mol· cm^-2 and the area occupied by each CF molecule was 2.64 nm^2. The adsorption obeys Langmuir adsorption isotherm. The adsorption coefficient β, Gibbs energy of adsorption △G^θat 25 ℃ ,the number of electrons transferred n, kinetic parameter of the irreversible system ano and the rate constant of surface electrode reaction ks are 1.06×10^6, --32.13 kJ·mo1^-1, 2,1.44 and 0.26 s^-1 respectively. The optimum conditions for detecting CF by adsorptive stripping voltammetry was proposed and the detection limit was 2. O×10^-8 mol·L^-1.