Biomass ashes contain valuable elements for plant growth, but also often high amounts of harmful heavy metals which limit their reuse in forests and on grassland. For monitoring metal concentrations, a fast and reliable method allowing the quantitative determination even at trace levels is mandatory. Therefore an analytical method consisting of an acidic microwave assisted digestion prior to ICP-OES measurement was optimized. The elements of interest were Al, As, B, Ba, Cd, Co, Cr, Cu, Fe, Mg, Mn, Na, Ni, Pb, Sb, Sr, Ti, V, and Zn. A validation including the following parameters was performed for each analyte: limit of detection, limit of quantification, recovery by spiking experiments, accuracy by analyzing a certified reference material, reproducibility (wihtin-24 hours, 4 and 7 days), linearity, and uncertainty of measurement. Two standards series were used for calibration – one with 1 M HNO3 and one with additionally 2 g/L Mg(NO3)2 to investigate the elimination or decrease of possible matrix effects. Both calibration methods showed very good recoveries. The method optimized allows the determination of the relevant elements covered by the recommendation of the Austrian ministry for agriculture and represents thus an appropriate tool for monitoring the metal contents in biomass ashes.
|Journal||Journal of Chemistry and Chemical Engineering|
|Publication status||Published - Jun 2011|
- method validation