Iodine was used as an oxidant instead of brimine in the 2,4-dinitro-phenylhydrazine method for the determination of total ascorbic acid content in vegetables. The excess of iodine was removed with a small amount of crystalline thiourea. This process of oxidation was simple, safe and rapid.With this modified method, the ascorbic acid content of 18 vegetables were determined. The ascorbic acid values thus obtained with iodine were sometimes slightly lower than those with bromine, but were higher than those with paper chromatographic method.

(1) The contents of total ascorbic acid in 129 kinds of vegetables and fruits in Kaifeng were determined by means of both Kuo-Chen's paper ch-romatographic method and Schaffert-Kingsley's 2,4-dinitrophenyIhydrazine colorimetric method.(2) Our results indicated that the 2,4-dinitrophenylhydrazine colorimetric method was not specific in determining the total amount of ascorbic acid contents in acid extracts of vegetables and fruits and thus usually gave false results. Such extracts must be first separated from interfering substances before determination. Kuo and Chen's paper chromatog-raphic method is most suitable for this purpose.