示波测定新方法的研究

A study on the new methods in oscillographic determination

报道了近期示波测定新方法的研究,包括酒中半胱氨酸含量直接测定、茜素红S(ARS)及Ca-ARS的示波特性及应用、头孢氨苄降解过程和检测大豆甙元清除活性氧自由基能力4方面的研究工作。建立了2次微分简易示波伏安法直接测定酒中半胱氨酸含量的新方法,线性范围3.0×10-6～5.0×10-5mol/L,检出限为1×10-4mol/L;研究了0.1 mol/L KOH底液中ARS及Ca-ARS的示波特性;测得配合物的配位数为Ca:ARS=1:2,配合物的条件稳定常数估测为1.5×109。结合极谱研究说明了该切口是由配合物中ARS还原产生的,该法可成功应用于含钙药物葡萄糖酸钙口服液及片剂中钙含量的测定;研究了头孢氨苄在1 mol/L NaOH溶液中的降解过程。反应速率方程式表明,降解过程为一级反应,降解反应速率常数k=0.056 min-1,半衰期t1/2为12.38 min。讨论了O2-·的产生及大豆甙元异黄酮化合物对O2-·的清除作用,表明大豆甙元是一种有效的自由基清除剂。

Some new methods in oscillographic determination were presented, including direct determination of cysteine, the oscillographic behaviors of alizarin red S(ARS) and Ca-ARS and its application,the degradation process of cephalexin and daidzein scavenging superoxide radical (O2 - · ) produced by the autoxidation of pyrogal-lol. Second order differential simple oscillographic voltammetry was found for the determination of cysteine in wines. The linear range of cysteine was 3. OX 10-6-5. 0× 10-5 mol/L. The detection limit was 1 × 10-6mol/L. The oscillographic behavior of alizarin red SCARS) and Ca-ARS has been investigated in 0. 1 mol/L KOH solution. It was found that the complex formed by Ca2+ with ARS with the stoichiometry of 1 : 2,and the condition formation constant was determined as β=1. 9× 109. The results showed that the molecule of ARS was adsorpt-ed on the electrode surface in the form of negtive ion. The method was applied to the content determination of calcium gluconate in its oral liquid and tablet. The studies on degradation process of cephalexin showed it was the first order reaction, rate constant and hale life in 1 mol/L NaOH estimated 0. 056 min-1 and 12. 38 min,respectively. Sdudies on daidzein showed in HCl-Tris CpH8. 30) buffer solution,it can scavenge superoxide radical CO2-· )produced by the autoxidation of pyrogallol.