Describes gas chromatographic methods for pentachlorophenol, pentachlorophenol laurate, γ-hexachlorocyclohexane and dieldrin, and describes colorimetric methods for pentachlorophenol and pentachlorophenol laurate.

This Part of BS 5666 describes procedures for the quantitative determination of pentachlorophenol (PCP), pentachlorophenyl laurate (PCPL), γ-hexachlorocyclohexane (γ-HCH) and dieldrin present in preservative solutions and treated wood. Both colorimetric and gas-liquid chromatographic (GLC) methods are given for the determination of PCP and PCPL but only a GLC method is given for the determination of γ-HCH and dieldrin as no suitable specific chemical methods are available for these chlorinated hydrocarbon insecticides.

The GLC method is suitable for the determination of the total amount of PCP, PCPL, γ-HCH and dieldrin within a single sample of wood. It may be used to study the distribution of these components through such a sample. Since the preservative solution, or the solution obtained by extraction of treated timber, is diluted to a suitable concentration for analysis, a wide range of concentrations may be assessed. In treated timber, at the lower end of the range, loadings down to 0.001 % (m/m) have been determined by this method. However, at very low loadings, where little or no dilution is required, it is necessary to consider the possibility of interference from what are normally minor constituents of the system (e.g. wood extractives or solvent impurities).

The colorimetric method is suitable for the determination of PCP or PCPL in solutions or extracts from treated timber containing γ-HCH, dieldrin, tributyltin oxide (TBTO), copper naphthenate, zinc naphthenate, disodium octaborate and wood extractives.

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

CAUTION. Attention is drawn to the general safety precautions mentioned in clause 4 of Part 1 of this British Standard and also to the specific hazard warnings given in 2.2.7, 2.2.12 and 2.3.2 of this Part.