BS 5666-3:1991

Two methods: atomic absorption spectrometric and colorimetric.

This Part of BS 5666 details procedures for the determination of copper, chromium and arsenic in preservatives and in treated timber containing those water-borne preservative compositions which consist essentially of copper, chromium and arsenic compounds. The wood sample may be in the form of sawdust, wood flour, or thin sections. There is no inter-elemental interference during the determinations and the procedures are specific for arsenic even in the presence of phosphorus compounds.

The procedure for the analysis of preservatives has been primarily designed for solutions complying with the requirements of BS 4072; 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. The digestion procedure has been designed to deal with wood samples up to 8 g in mass, but it may be necessary to adjust the concentration of the resulting solution before a satisfactory analysis can be carried out.

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

NOTE The titles of the publications referred to in this standard are listed on the inside back cover.