毛髪中の微量元素に関する研究(第1報)フレームレス原子吸光分析による毛髪中カルシウムの定量とその含有量の変動

抄録

It has been noted that the contents of trace elements in hairs vary with difference of position in the same head, age, sex, hair cosmetic treatment and enviromental pollution. This paper describes the rapid analytical method of calcium in small hair segments (1 cm) using flameless atomic absorption spectrophotometry and the variation of calcium content in the hairs with the permanent wave treatment. Calcium was determined with the rocovery of 99% by ashing in platinum crucible followed by dissolving the residue in water by stirring with the glass covered magnetic spin bar. Loss of calcium was observed when the porcelain crucible or the glass flask was used as ashing ware, and the tefron covered magnetic spin bar caused contamination of calcium. The analytical results obtained by this method agreed with those of the other investigators determined by neutron activation analysis or atomic absorption analysis. In the hairs which had never permanent-waved the calcium concentrations were 200-1000 ppm and showed a general tendency to increase slightly from the root to the distal end of the hair. On the other hand, the permanent-waved hairs showed higher calcium concentrations (2000-4500 ppm). Adsorption of calcium on the treated hairs was dependent on pH, showing that after the hair previously treated with permanent wave reagents were soaked in city water (pH 6.8) calcium content increased and that no significant increase was observed by soaking in acidic calcium solution (pH 3). Calcium adsorbed on the treated hairs was removed by soaking in dilute hydrochloric acid (1→20). The above results suggested that permanent wave treatment is responsible for increasing ionexchangeable calcium in the hair.