Kamangar T, Fawzi A B, Maghssoudi R H
J Assoc Off Anal Chem. 1977 May;60(3):528-30.
A new spectrophotometric method has been developed for determining ascorbic acid in citrus fruits. The method is based on interaction between dimethoxydiquinone and ascorbic acid, followed by extraction with chloroform. The resulting chloroform solution gives a maximum absorption at 530 nm, a determination limit of 22.0 microng/ml, and a linear range from 22.0 to 97.5 microng/ml. The molar absorptivity of the chloroform solution was 1.62 x 10(3). The reaction was quantitative over the pH range from 3.0 to 7.0. Ascorbic acid in citrus fruits was successfully determined by this method. Comparison of results with those obtained by using the AOAC method showed excellent agreement; the average recovery for the analysis of orange, grapefruit, and lemon juices was 100 +/- 0.3%.
已开发出一种用于测定柑橘类水果中抗坏血酸的新分光光度法。该方法基于二甲氧基二醌与抗坏血酸之间的相互作用，随后用氯仿萃取。所得氯仿溶液在530nm处有最大吸收，测定限为22.0微克/毫升，线性范围为22.0至97.5微克/毫升。氯仿溶液的摩尔吸光率为1.62×10³。该反应在pH值3.0至7.0范围内是定量的。用该方法成功测定了柑橘类水果中的抗坏血酸。将结果与采用美国官方分析化学师协会（AOAC）方法获得的结果进行比较，显示出极佳的一致性；橙汁、葡萄柚汁和柠檬汁分析的平均回收率为100±0.3%。
