Digestion Procedures for the Elemental Analysis of Wood by Inductively Coupled Plasma Optical Emission Spectrometry

Abstract

ABSTRACTVarious digestion methods are available for the elemental analysis of wood biomass. Microwave digestion is the current European standard method for the determination of major and minor elements in solid biofuels. Because of the small masses (≤0.5 g) employed in microwave digestion, the resulting analyte concentrations in solution are low, and inductively coupled plasma mass spectrometry (ICP-MS) may be necessary to provide the required low limits of detection. However, higher concentrations are required for inductively coupled plasma optical emission spectrometry (ICP-OES) compared to ICP-MS. In this work, wet, dry, ash fusion, and microwave digestion were employed to determine Al, Ca, Fe, Mg, P, K, Si, Na, S, Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn in wood biomass by ICP-OES. Two certified reference materials (BCR 100, beech leaves and BCR 62, olive leaves) were used in this study. The concentrations of Cd, Co, Cr, Cu, Ni, and Pb were below the limits of quantification for ICP-OES. Wet digestion was suitable for the elemental analysis of wood biomass by ICP-OES with the exceptions of Al and Si. Dry digestion was accurate for some elements and ash fusion was the most accurate for the determination of silicon.