Preparation and certification of human hair powder reference material.

Human hair powder reference material was prepared and certified for elemental composition. Human scalp hair (from Japanese men) was washed in a non-ionic detergent solution in an ultrasonic cleaner, dried, ground in an agate ball mill, sieved through a polyethylene net, blended, bottled (1100 vials, 2 g each), and finally sterilized by 60Co radiation. The prepared material satisfied the homogeneity criteria for a reference material. We determined trace elements by inductively coupled plasma atomic emission spectrometry and atomic absorption spectrometry and investigated matrix interference effects. The material was certified by using the data obtained by various analytical techniques; certified values are provided for Ca, Cd, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Sr, and Zn. The elemental composition of this reference material is considered similar to normal values for the male Japanese population.