Chromatographic studies on preservatives in the wood of some conifers, especially of the genus Abies, Picea and Pinus

Abstract

The detection of five commercial wood preservatives in various wood extracts was investigated using thin-layer and gas-liquid chromatography. Studies were made on chloroform extracts of wood from 46 species, mainly from the coniferous genera Abies, Picea and Pinus using thin-layer chromatography. The preservatives tributyltin oxide, o-phenylphenol, benzene hexachloride, pentachlorophenol and polychloronaphthalene were best separated on Silica Gel G with ethyl acetate- n-hexane (15:85) as a running solvent. Diiodofluorescein was found to be a useful general locating reagent for all of the preservatives examined and o-phenylphenol was found to be more readily detected than the other preservative compounds, whereas tributyltin oxide was the most difficult to locate, and it was not possible to identify this compound in the presence of several of the wood extracts. Using gas-liquid chromatography, a column packed with 10% LAC-3-R-728 on Chromosorb W was found to be suitable for the identification of three or four of the preservatives, but the polychloronaphthalene sample gave eighteen peaks on the chromatogram, and this large number of impurities prevented identification of the polychloronaphthalene itself. The suggested combination of thin-layer and gas-liquid chromatography provides a suitable method for the detection of the above preservatives in a large number of species of wood.