Two methods: atomic absorption spectrophotometry and colorimetry using zinc dibenzyldithiocarbonate.

This Part of this British Standard details procedures for the determination of copper naphthenate, expressed as the amount of copper present, in preservatives and in treated timber containing this preservative. The methods have been found suitable for the determination of copper in the presence of tributyltin oxide, pentachlorophenol, o-phenylphenol, monochloronaphthalene, polychloronaphthalene, γ-HCH, dieldrin, zinc naphthenate, potassium salts and sodium salts. The wood sample may be in the form of sawdust, wood flour, or thin sections.

The procedure for the analysis of preservatives has been primarily designed for solutions complying with the requirements of BS 5056; for samples of other compositions it may be necessary to make adjustments. It is difficult to make recommendations as to the quantity of sample to be taken in the case of treated wood because the predominant factor is the quantity of preservative within the wood rather than the mass of the wood itself. It may thus be necessary to make some adjustment to the values quoted in the standard, either to the mass of the treated wood sample taken for analysis or to the level of dilution of the copper solution resulting from extraction.

Two methods are described, the first involving atomic absorption spectrophotometry and the second colorimetry.