Fast analysis of wood preservers using laser induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is used for the investigation o f wood preservers in timber and in furniture. Both experiments in laborator y and practical applications in recycling facilities and on a building site prove the new possibilities for the fast detection of harmful agents in wo od. A commercial system was developed for mobile laser-plasma-analysis as w ell as for industrial use in sorting plants. The universal measuring princi ple in combination with an Echelle optics permits real simultaneous multi-e lement-analysis in the range of 200-780 nm with a resolution of a few picom eters. It enables the user to detect main and trace elements in wood within a few seconds, nearly independent of the matrix, knowing that different ki nds of wood show an equal elemental composition. Sample preparation is not required. The quantitative analysis of inorganic wood preservers (containin g, e.g. Cu, Cr, B, As, Pb, Hg) has been performed exactly using carbon as r eference element. It can be shown that the detection limits for heavy metal s in wood are in the ppm-range. Additional information is given concerning the quantitative analysis. Statistical data, e.g. the standard deviation (S .D.), were determined and calibration curves were used for each particular element. A comparison between ICP-AES and LIBS is given using depth profile correction factors regarding the different penetration depths with respect to the different volumes in wood analyzed by both analytical methods. (C) 2001 Elsevier Science B.V. All rights reserved.