摘要：1. Human hair treated with cold-waving lotions, hair bleaching lotions, synthetic organic hair dyes, or depilatories was hydrolyzed with hydrochloric acid, and the hydrolyzed solution was submitted to amino acid autoanalyzer. Determined values of various amino acids were compared with the values of normal hair. A marked depletion of cystine and formation of cysteic acid were observed in the hair treated with cold-waving lotions, hair bleaching solutions, and synthetic organic hair dyes. Formation of cysteic acid was not observed in the hair treated with a depilatories but there was a marked decrease in cystine, with formation of a trace of methionine sulfoxide and methionine sulfone. 2. Amino acids formed by the decomposition of keratin when human hair is treated with cold-waving solutions or hair bleaching solutions were determined, both qualitatively and quantitatively, by amino acid autoanalyzer. Damaging effect of these solutions on the hair was proved by the dissolution of various amino acids.
