Cd^(2+)用于复合维生素B片剂中烟酰胺的示波测定

Application of Cd^(2+) to Oscillographic Determination of Nicotinamide in Compound Vitamin B Tablets

在0.05 mol.L-1Na2B4O7-0.05 mol.L-1KNO3溶液中,Cd2+能够产生灵敏切口且该切口深度随烟酰胺-Cd2+络合物量的增加而变浅。根据Cd2+的这一示波特性,建立了用二次微分简易示波伏安法间接测定烟酰胺含量的新方法。在选定实验条件下,测得Cd2+在二次微分简易示波图上的峰高与烟酰胺浓度在3.0×10-6~6.5×10-5mol.L-1范围内呈线性关系,检出限为1.5×10-6mol.L-1;对于3.0×10-5mol.L-1烟酰胺测定的相对标准偏差为2.3%(n=5)。与其他方法相比,本方法具有仪器简单、方法简便快速、无需通氮除氧等特点。

In 0.05 mol · L ^-1 Na2B407- 0.05 mol · L ^-1 KNO3 solution, Cd2 ＋ can yield a sensitive incision on the oscillogram. This incision would get shallow with increasing concentrations oil the complex formed between nicotinamide and Cd^2＋. Based on this oscillographic characteristic, a new method for the determination of nicoti- namide in compound vitamin B tablet by the second-order differential simple oscillographic voltarnmetry is developed. Under the optimal experimental condition, a linear response is observed in the range of 3.0 × 10^-6- 6.5 × 10 ^-5 mol · L ^-1 with a - 0. 994 0 correlation coefficient and a 1.5 × 10 ^-6 mol · L ^-1 detection limit for nicotinamide. The RSD is 2.3% for the determination of 3.0 × 10 -5 mol · L ^-1 nicotinamide by this method （n = 5） . Compared with other methods, the second-order differential simple oscillographic voltarnmetry is fast and convenient due to its cheap equipment and no need for O2-eliminated