间接分光光度法测定药品中VC含量

The Determination of the Content of Vitamin C in Medicine by Indirect Spectrophotometry

利用VC的还原性,将Fe3+定量转化为Fe2+离子,产生的Fe2+与邻菲啰啉形成橘红色络合物,从而间接测定VC的含量。结果表明,络合物在510nm处有最大吸收峰,且显色物的浓度在2.0×10-6-5.0×10-5mol/L范围内与吸光度成正比,其相关系数R为0.9936,检出限为2.0×10-6mol/L,被测定样品的RSD小于5.0%,回收率为99.0%-104.0%。该方法简便快速,准确,重现性好,适用范围广。

VC reduces Fe （III） to Fe （II） quickly and the latter reacts with 1, 10-pHenanthroline monohydrate to form a reddish colored complex with its absorption maximum at the wavelength of 510 nm. Under the optimal determination condition, a good linear of this method is observed in the range of 2.0×10^-6-5.0×10^-5mol/L. The correlation coefficient（r） is 0.9936, the detection limit is 2.0×10^-6aol/L, the RSD of the determined samples is less than 5.0%, and the recovery is 99.0%-104.0%. This method is simple, rapid, and accurate and has good reproducibility, which can be used widely to determine the content of VC in samples.