DETERMINATION OF ALUMINUM IN HUMAN BRAIN-TISSUE BY ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY

Brain tissue is rich in phosphorus and alkali and alkaline earth metals. A synergistic interference has been observed with the determination of aluminium by electrothermal atomic absorption spectrometry when phosphorus is present in the sample along with alkali or alkaline earth metals. For the determination of aluminium in human brain samples, potassium dichromate was found to be an effective chemical modifier. The concentration of aluminium in National Institute of Standards and Technology (NIST) Standard Reference Materials (SRMs) Citrus Leaves (SRM 1572), Oyster Tissue (SRM 1566a) and in National Institute for Environmental Studies (NIES) Certified Reference Material (CRM) No. 6 Mussel were determined. Values of 76.6+/-4.2, 86.8+/-0.5 and 55.5+/-10.1 mug g-1 were obtained before the use of the modifier, and 88.2+/-6.2, 197.7+/-6.8 and 215.0+/-12.5 mug g-1 after the use of potassium dichromate as chemical modifier for Citrus Leaves, Oyster Tissue and Mussel, respectively. The concentrations of aluminium determined with the use of potassium dichromate as chemical modifier are in good agreement with the certified values in the standard samples. The aluminium contents of several human brain samples were also determined. Values ranged from 6.2 to 9.8 mug g-1 of aluminium (dry mass basis).