MICROWAVE DIGESTION METHODS FOR THE ATOMIC SPECTROMETRIC DETERMINATION OF SOME ELEMENTS IN BIOLOGICAL SAMPLES

Four closed microwave-based digestion procedures have been tested on b iological samples for application in the determination of P, B, Cu, Fe , Mn, Zn, Cd and Pb by inductively coupled plasma atomic emission spec trometry, flame atomic absorption spectrometry or electrothermal atomi c absorption spectrometry. The proposed methods involve either wet oxi dation with nitric acid alone or in combination with HF, H2O2 or HClO4 . Their accuracy was assessed by analysis of Standard and Certified Re ference Materials or by comparison with results from conventional dige stion procedures. The results provide quantitative recoveries for most elements and the precision ranged from +/- 3 to +/- 15% relative stan dard deviation indicating that the methods employed were well suited f or the sample types investigated.