Analysis of hair by electron spectroscopy for chemical analysis

Abstract

An exploratory study is presented evaluating electron spectroscopy for chemical analysis (ESCA) as a tool for studying human hair. ESCA provides valuable information about the hair surface to a depth of 20 to 30 angsttoms, and ESCA is especially useful for studying the oxidation of disulfide sulfur in hair. ESCA can also be used to study the removal of lipid from hair and/or the adsorption of ingredients to hair such as sulfate-containing surfactants. A primary reaction in the weathering of human hair involves degradation ofdisulfide sulfur, and ultraviolet radiation is a principal cause of this degradation. This reaction occurs primarily at or near the hair surface and appears to involve degradation of cystine residues via the C-S fission mechanism. Chemical bleaching of disulfide in hair by alkaline hydrogen peroxide is different and appears to proceed through the S-S fission route.