Microwave digestion methods for the atomic spectrometric determination of some elements in biological samples

Abstract

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