头孢氨苄的示波极谱研究

SINGLE SWEEP OSCILLOPOLAROGRAPHIC STUDIES OF CEPHALEXIN

头孢氨苄(CEX)本身不具电活性,经NaOH溶液中加热降解后,在0.1mol·L^(-1)NaOH中得一灵敏的示波极谱还原峰,峰电位为-0.82 V(vs.SCE),峰电流与CEX浓度在0.1～1.5 μmol·L^(-1)范围内成线性关系,检出限为0.05μmol·L^(-1),相关系数为0.9999.用线性扫描与循环伏安法、脉冲极谱和恒电位电解法等研究体系的电化学行为.实验表明,体系属准可逆吸附.

Cephalexin is a nonelectro active species. The degradation product of cephalexin after intensive hydrolysis in sodium hydroxide for 20 min at 100℃ can be reduced. In 0.1 mol·L^(-1) NaOH a sensitive peak of cephalexin is obtained by single -sweep polarography. The peak potential is-0.82 V (vs. SCE).The peak current is directly proportional to the concentration of cephalexin over the range of 0.1~1.5μmol ·L^(-1).The detection limit is 0.05μmol·L^(-1).The electrochemical behaviour of the degradation product of cephalexin is studied by means of linear sweep and cyclic voltammetry, constant-potential coulometry, Npp, etc. This indicates the quasi-rever- sible adsorption wave.