Quantification of copper and chromium in field stakes after different exposure times: Remaining metal content and distribution
T Liese, M Bahmani, E Melcher
In order to determine the distribution of copper and chromium as well as their remaining concentration EN 252 specimens and thicker pine sapwood stakes (non standard format) were treated with a commercial CC salt in a vacuum pressure process. The stakes were installed in the test field of the Institute of Wood Research, Hamburg, in August 2010. In all cases three stakes were removed after 4, 8, 12, 16 and 20 months of exposure, whereby the metal content was analysed after sample preparation. Based on these data and under consideration of the analytical values of unexposed stakes the remaining metal content was calculated for the above and in ground section. The results illustrate that 84 % of the copper remained in the full EN 252 samples and 77 % in the non standard stakes whereas the chromium content corresponds to 95 % and 85 %, respectively. On the other hand the data illustrate that in both sample sizes the highest copper and chromium amount was found in the above ground portion after exposure.
Keywords: wood preservative, field test, chemical analysis, remaining metal content