Difference in the distributions between Ca content and the degree of oxidative damage in human hair determined by x ray imaging
In order to examine the cause of Ca distribution in human hair, the distributions of Ca and oxidation of cystine, a major sulfur containing amino acid in hair, were compared in submicron resolution with X ray spectromicroscopy at the Ca K and S K absorption edges. Ca distribution was also detected with high sensitivity by X ray Fluorescence Analysis (XRF) in a few micron resolution. Hair samples were treated with bleach followed by Ca soaking. The increase of Ca content was in parallel with the progression of the oxidation by bleach treatment, beginning from the cuticle, the outer region of the hair. This increase was dependent on the concentration of bleach solution and treatment time. On the other hand Ca content in medulla, the central region of the hair, was apparent even in hair with no bleach treatment, and seemed to be little influenced by the Ca soaking following bleach treatment.