MICROWAVE-OVEN DIGESTION PROCEDURE FOR ATOMIC-ABSORPTION SPECTROMETRYANALYSIS OF BONE AND TEETH

The purpose of this study was to develop a new method for determinatio n of the mineral element in teeth and bone using a microwave digestion procedure coupled to atomic absorption spectrometry. Samples were ash ed at 450 degrees C for 4.5 h and subsequently digested in a microwave oven at maximum power (600 W) for 10 s using a Teflon closed Parr bom b. This method permits the rapid dissolution of the biological samples , avoiding operations such as slicing and cutting which often introduc e alterations in sample homogeneity and may contribute to their contam ination. The analysis of Na, K, Ca, Mg, Fe, Zn, Ba, Cd and Pb showed g ood reproducibility, precision and accuracy as compared with the certi fied values fdr the IAEA H-5 animal bone. Average concentration for th ose elements in permanent teeth obtained from children aged 11-18 year s by orthodontics are given.