1.5次微分吸附阴极溶出伏安法测定毛地黄毒苷及其电极过程的探讨

Determination of Digitoxin by 1.5' Differential Absorptive Cathodic Stripping Voltammetry and Its Electrical Process

毛地黄毒苷是治疗心脏病的有效药物,它在汞电极上能吸附还原.以1.5次微分吸附阴极溶出伏安法测定检出限达3.2×10^(-10)mol/L.吸附溶出响应依赖于试液浓度、富集电位、富集时间、介质、溶液pH、温度及扫速等因素.不同富集时间,不同浓度范围内.浓度与峰高有良好的线性关系.毒苷的常规循环伏安图上出现两对氧化还原峰,电极反应相似于α,β不饱和羰基的1,2和1,4加成,电极反应可逆.毒苷在汞电极上的饱和吸附量为3.54×10^(-11)mol/cm^2.

Digitoxin, one of the cardiac glycosides, can be absorbed strongly in mercury electrodes. When it is accumulated to the surface of HMED prior to 1.5' differential cathodic stripping voltammetry, the detection limit of 3.2×10-10mol/L is readily achieved. The absorptive stripping response is evaluated with respect to acccumulated time and potential, concentration dependence, electrolyte, pH, scanning rate, temp. etc. The results of digi-toxin injection sample determination are satisfied. Two couples of redox peaks are observed on its cyclic voltammogram and the mechanism is discussed. The saturated absorptive quantity on the HMED is 3.54×10-11mol/cm2.