还原分光光度法测定果蔬中的维生素c

Vitamin C was Determined by Reductive Spectrophotometry in Fruits and Vegetables

在pH6.0的HAc-NaAc缓冲介质中 ,维生素c将Fe(Ⅲ ) -α,α′ -联吡啶还原为Fe(Ⅱ ) -α,α′ -联吡啶 ,加入十二烷基苯磺酸钠 (LAS)后 ,进一步提高了它的灵敏度 ,其最大吸收波长在 5 2 1nm处 ,维生素c的质量浓度在 0～ 1 2 μg .mL- 1内服从比耳定律 ,北回归方程为A =0 .1 1 0 4c +0 .0 0 3 9,相关系数γ为 0 .9981。用于果蔬中的维生素c的测定 。

In HAc-NaAc buffer medium(pH=6.0)Iron(Ⅲ)-α,α′′-bipyridine is reduced by citamin c to form lron(Ⅱ)-α,α′-bipyridine in the presence of Moina Macrocopa(LAS)to make furher improvement on its sensitivity.This compound has amaximum absorption at 521nm.The Beers law was obeyed in the ascorbic acid concentration range of 0-12lμg·mL -1 with the equation A=0.1104c+0.0039 and its relative coefficient γ is 0.9981.The proposed new method was applied to the determination of vitamin c in several kinds of fruits and vegetables with satisfactory results.