中文摘要：

基于将测定抗坏血酸的碘滴定（药典）法和铁铵矾滴定法相结合，即先用铁铵矾基准物氧化碘化钾置换出相当量的12，再在维生素C药物溶液滴定中让相当量的12定量氧化抗坏血酸。合适的反应条件是：乙酸介质，碘离子过量，室温置暗处置换反应10min。将该法用于维生素C药物中抗坏血酸的测定，结果与药典法结果相符。

英文摘要：

It was proposed that the ascorbic acid in vitamin C （VC） tablets or injections was determined in the following steps; （1） a definite amount of ferric ammonium sulfate （primary standard） was dissolved in dil. HOAc solution, and an excess amount of KI was added, and the solution was kept in derk for 10 min for quantitative liberation of iodine （as I3^- ） ; （2） a definite amount of the sample of VC tablet or injection was dissolved in 200 mL of 0. 1 mol · L^-1 HOAc solution, which was used as titrant to react with the iodine （as I3^- ） liberated in the former step. Consistents results were obtained by this method and the pharmacopoeia method.