The analysis of hair keratin

Abstract

The influence of the order of separation of the amino-acids from a human-hair hydrolysate upon their quantitative isolation was investigated. A suitable order of separation of the dicarboxylic and dibasic amino-acids was reported. Aspartic acid (3.5%) was isolated for the first time from human hair. Glutamic acid was isolated from human hair in higher yields than previously reported. The quantities of basic amino-acids isolated agreed essentially with those reported in the literature. Methionine was found in human hair, and its amt. detd. as 1.0%. The unexpected finding of methionine in a fraction derived from a caiefully washed and reprecipitated cuprous mercaptide precipitate casts some doubt upon the universal applicability of the method of estimating cystine by the organic S content of this precipitate.