甲磺酸吉米沙星的吸附伏安特性及其应用

Adsorptive Voltammetric Behavior of Gemifloxacin Mesylate and Its Application

在特定缓冲底液(pH6.40)中,甲磺酸吉米沙星(Gemifloxacin mesylate,简称FACTIVE)在汞电极上可以发生还原反应,测得了还原反应的峰电位,该还原峰为典型的吸附峰;测定表明,吸附于滴汞电极上的粒子为甲磺酸吉米沙星的中性分子,通过实验测得了待测物在滴汞电极汞滴上的饱和吸附量,测得了FACTIVE分子在汞滴上吸附后所占电极面积,实验证明待测物中性分子在汞滴上的吸附符合Langmuir吸附等温式;实验表征了吸附系数,25℃时的吸附自由能,电极反应过程中转移电子数,不可逆体系动力学参量,汞滴表面反应速率常数;并通过实验给出了吸附溶出伏安法测定FACTIVE的最佳条件,方法的检出限满足常规分析的要求.

In a supporting buffer solution of （ pH6.40 ）, a reduction peak of Gemifloxacin mesylate （ FACTIVE ） with a potential and adsorptive characteristics was observed by linear sweep voltammetry at Hg electrode. The adsorbed species are most probably the neutral molecules of FACTIVE. The saturated adsorption occupied by each molecule at Hg electrode for FACTIVE were obtained. On the surface of the hanging mercury drop electrode, the adsorption obeys langmuir adsorptiom isotherm. The adsorption coefficient β, the Gibbs energy of adsorption △G^θat 25 ℃, the number of electrons transferred n, the kinetic parameter of the irreversible system anα and the rate constant of surface electrode reaction, respectively. A method for the assay of FACTIVE was proposed by adsorptive stripping voltammetry. The detection limit of the method is satisfying the conventional analysis.