Abstract
The color reaction of 6-deoxy-hexoses by sulfuric acid was examined in order to apply to the spectrophotometric determination of these sugars. The procedure includes heating a mixture of 2ml of sample and 4ml of 81_??_82 wt.% sulfuric acid for 20 minutes in boiling water and measuring the optical density at 458 mμ. The optical density showed a linear relationship to the concentration over the range of 50_??_140, μg/2 ml of rhamnose, and the standard deviation being 0.002_??_0.004 in optical density. Presence of small amount of other hexoses, pentoses, and uronic acids gave little effect under the condition used. When larger amount was contained, the result can be calibrated by the optical density at 530 mμ. Little or no effect resulted by other substances tested, except dichromate, nitrate, tannic acid, and ascorbic acid, which could significantly interfere if large amount was present
