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 modifier allows a compromise higher pyrolysis temperature to be used for the simultaneous detection of chromium (Cr), copper (Cu), iron (Fe), manganese (Mn) and lead (Pb) in various human hairs by graphite furnace atomic absorption spectrometry (GFAAS). The recommended pyrolysis temperature for all of the analyte elements is 1000 degrees C (ashing) and 2800 degrees C (atomizing). Nitric acid (HNO3) and perchloric acid (HClO4) were used for the digestion of all human-hair samples. The detection 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 accuracy and precision were examined by analyzing a certified reference material (NIES CRM No.13 Human Hair). All of the analytical results obtained by the proposed method were in good agreement with the certified values. The relative standard deviation (RSD) was less then 8 %.