The present author found that ascorbic acid produces the reddish orange color by BrCN and NaOH. The maximum absorbancy of the color was 520 mμ which changed to 505mμin the course of time. Similar reaction was recognized when iodine, bromine, N-bromosuccinic acid, potassium ferricyanide or ascorbic acid oxidase was used as oxidant in place of cyanogen bromide, simultaneous addition of antioxidant such as KCN or SnCl_2.
