Abstract
A method using pyrogallol-ferric chloride-hydrochloric acid-acetic acid reagent was described for the colorimetric determination of pentose, pentosan, or ribonucleic acid. Coloration by this method was 90% in D-ribose and 54% in L-arabinose of that of D-xylose. Pentoses can be determined up to 10∼50μg./ml. Hexuronic acid showed an absorption curve similar to that of pentoses but its coloration was much lower than that of pentoses. It is possible to eliminate the influence of other carbohydrates by estimating the difference in absorbances between 500 and 430 mμ. The presence of D-glucosamine, serum albumin, and sodium chloride does not interfere in this coloration.
