MICROWAVE DIGESTION METHOD OF SOIL SAMPLES FOR TOXIC ELEMENTS ANALYSIS BY ICP-MS TECHNIQUE

A microwave digestion method utilizing an acid mixture of HF, HCl, and HNO3 was developed for thedetermination of the total content of seventeen elements (As, Ba, Be, Cd, Cr, Cu, Pb, Ni, Ag, Zn, Mn, V,Sn, Co, Sb, U and Mo) in soil samples employing inductively coupled plasma mass spectrometry (ICPMS).A methodology was evaluated for the precision and accuracy by the analysis of standard referencematerial (IAEA SOIL-7). The results obtained via the proposed method are in good agreement with thecertified values. T-test statistical treatment showed that, there is no significance differences between theaccuracy of both results at 95% confidence levels for all elements. Relative standard deviation rangedbetween 1-11% and a percentage recovery in the range 97-109% was obtained. A comparison between the proposed method and the wet digestion method as a standard method using the same standard reference material (IAEA SOIL-7) and the acid mixture (HF/HCl/HNO3) showed that there is no significance difference between the precision of both results at 95% confidence level.