间接分光光度法测定药物中的维生素E

Determinnation of Vitamin E in Drugs by Indirect Spectrophotometry

在表面活性剂CTMAB存在下,维生素E能够定量将Fe(Ⅲ)还原为Fe(Ⅱ)离子,利用显色剂5-硝基-1,10菲咯啉建立了间接分光光度法测定维生素E的方法,在pH 4.6的乙酸-乙酸钠缓冲溶液中,Fe(Ⅱ)-5-硝基-1,10-菲咯啉络合物的最大吸收峰位于502nm处,维生素E的含量在0.3—2.0 mg·L-1范围内符合比耳定律,表观摩尔吸光系数ε502=2.43×104L·mol-1·cm-1。本法用于维生素E片剂、胶丸及注射液中维生素E含量的测定,与药典法对照,2种方法所得结果一致。

A spectrophotometric method for the indirectly determination of vitamin E was developed based on the complexation of 5-nitro-1,10-phenanthrolin and Fe（Ⅱ）.In an acetate buffer of pH 4.6,and in the presence of CTMAB,Fe（Ⅲ）was quantitatively reduced by vitamin E to Fe（Ⅱ）.The absorption peak locates at 502nm,and the molar absorptivity（ε502）is 2.43×104L·mol-1·cm-1.Beers law was obeyed in the range of 0.3—2.0mg/L of Vitamin E.The content of vitamin E in the soft content,tablets and injection were analyzed by the proposed method,results were in consistent with those obtained by the pharmacopoeia method.