烟酰胺极谱行为的研究

Study on the Oscillopolarography of Nicotinamide

用单扫示波极谱法，烟酰胺（ＮＡ）在ＫＨ２ＰＯ４－Ｎａ２Ｂ４Ｏｒ－ＮａＯＨ（ｐＨ＝１１．０）底液中呈现出良好的二阶导数峰，Ｅ″Ｐ＝－１．８０±０．０１Ｖ（ＳＣＥ），在５×１０－７～２×１０－５ｍｏｌ／Ｌ范围内，峰高与浓度成线性关系，检测限为２．２×１０－７ｍｏｌ／Ｌ。此法用于ＮＡ片剂含量的测定，其结果良好。当底液的ｐＨ值在１．９８～８．００之间时，ＮＡ有两个部分重叠的峰出现，其电极反应机理为伴有双聚反应的不可逆的逐级电子过程。实验证明自由基阻聚剂能有效地抑制ＮＡ的双聚反应，有助于深入了解这类常见电极反应过程。

By means of single sweep oscillopolarography,nicotinamide (NA) shows a well shaped 2nd order derivative reduction wave with a peak potential of -1.80±0.01V(SCE) in Kolthoff buffer solution.In the range from 5×10 -7 ～2×10 -5 mol/L,the height of nicotinamide depends linearly on the concentration and the detection limit is 2.2×10 -7 mol/L.The result was satisfactory when used to determine nicotinamide in tablets.There are two overlapping waves in the pH range of 1.98 to 8.00.The electrode reaction is an irreversible multistep charge transfer process involving dimerintion reaction.The experimental results showed that the dimerination could be inhibited by free radical inhibitor which was helpful to understand better this kind of electrode process.