采用褪色光度法测定维生素C

Determination of ascorbic acid by discoloration spectrophotometry

在硫酸介质中,利用维生素C(L-VC)对高锰酸钾的褪色效应建立了褪色光度法测定维生素C的方法。在最大吸收波长为526nm,表观摩尔吸收系数为6.71×103L·mol-1·cm-1时,维生素C浓度在0～20μg/ml范围内与溶液的褪色程度(△A)服从比尔定律,最小检出限为0.91mg/L,相对标准偏差为0.54%～0.96%,回收率为92.5%～101.8%。

A new method of determining ascorbic acid by discoloration spectrophotometry was established by using the discoloring effect of ascorbic acid （L-VC） on potassium permanganate in sulfuric acid medium. At the maximum absorption wavelength of 526 nm and the apparent molar absorption coefficient of 6.71 ×10^3 L·mo1-1· cm-1, Beer＇s Law was obeyed in the concentration of VC ranging from 0 to 20 μg·mL-1 and the discoloration degree（ΔA）. The detection limit was 0.91 mg/L, the relative standard