PIXE microanalysis in green hair

Abstract

PIXE microanalysis, a special X-ray fluorescence technique (PIXE = proton-induced X-ray emission), allows the determination of trace elements, such as copper and zinc, down to a level of 1 ppm. By means of this method cryo-sections of the hair shafts of a 25-year-old female patient suffering from the green hair syndrome were measured. The distribution of Cu, Zn, Ca and S in a 10 µm disk perpendicular to the hair axis could be evaluated. Our results showed a high content of Cu and Zn at the hair shaft periphery, whereas the center of the hair shaft was free of copper. Total concentration was: Cu 6638 ppm, Zn 1353 ppm, Ca 3004 ppm and S 43,788 ppm.

All other elements with an atomic number Z ≥ 14 were in normal range. After topical treatment with an aqueous solution of 1.5% 1-hydroxyethyl diphosphonic acid, the copper content was found markedly decreased in the periphery of the hair with 684 ppm. Zn and Ca were decreased too with 562 ppm and 867 ppm respectively, whereas the concentration of sulfur was nearly unaffected with 37,186 ppm. Our results show that in opposite to alternative methods, PIXE is able to detect and quantify trace elements in different areas of the hair shaft and as such, it is a most sensitive method to control therapeutic effects.