DETERMINATION AND CHARACTERIZATION OF COPPER, CHROMIUM AND ARSENIC INCHROMATED COPPER ARSENATE (CCA) TREATED WOOD AND ITS PYROLYSIS RESIDUES BY INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY

To dispose of chromated copper arsenate (CCA) treated wood waste, pyro lysis is a valuable method, In the context of a study aimed at optimis ing the pyrolysis of CCA treated mood, a method for the determination and characterisation of Cr, Cu and As in wood and its pyrolysis residu es was developed, Leaching and dissolution procedures mere applied and compared to determine the total amount of Cr, Cu and As in the dried wood and in the pyrolysis residue, A sequential extraction procedure w as also applied to the pyrolysis residue and confirmed that As is boun d to oxidised compounds, carbonates and the organic matrix, Copper sho wed a similar behaviour to As in the leaching environments considered, whereas Cr behaved in a totally different way, ICP-MS was used to det ermine Cu, Cr and As, Special attention was given to the analysis of t he organic matrices resulting from the sequential extraction procedure , To determine the oxidation state of As in the different extraction s teps, hydride generation coupled to ICP-MS was used, It could be seen clearly that As-III is far more mobile than As-V and that the As-V com pounds, originally present in the CCA solution and CCA treated wood, a re partly reduced to As-III compounds.