DETERMINATION OF CHROMIUM, COPPER, IRON, MANGANESE AND LEAD IN HUMAN HAIR BY GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROMETRY

The use of a combined mixed magnesium(Mg)-rhodium(Rh) chemical modifie r allows a compromise higher pyrolysis temperature to be used for the simultaneous detection of chromium (Cr), copper (Cu), iron (Fe), manga nese (Mn) and lead (Pb) in various human hairs by graphite furnace ato mic absorption spectrometry (GFAAS). The recommended pyrolysis tempera ture for all of the analyte elements is 1000 degrees C (ashing) and 28 00 degrees C (atomizing). Nitric acid (HNO3) and perchloric acid (HClO 4) were used for the digestion of all human-hair samples. The detectio n limits (3 sigma, ng g(-1)) were 0.3 for chromium, 0.1 for copper, 0. 4 for iron, 0.2 for manganese and 0.1 for lead, respectively. The accu racy and precision were examined by analyzing a certified reference ma terial (NIES CRM No.13 Human Hair). All of the analytical results obta ined by the proposed method were in good agreement with the certified values. The relative standard deviation (RSD) was less then 8 %.