scope:

This method is an analogue to AWPA Method A18, however, use of chloroform as a titration reagent has been eliminated and visual determination of a color endpoint has been replaced with a potentiometric endpoint using an automatic titrator. This method can be used to determine concentrations of quaternary ammonium compounds (quats) in wood. It is intended for routine quality control in wood treating and is not suitable for trace levels of quats in wood.

All cationic species that form sparingly soluble compounds with sodium lauryl sulfate can be determined quantitatively and therefore can also potentially interfere with the determination of quats. This method is not compound specific, the total equivalence of cationic compounds is determined. The molecular weight of the quat being studied must be known for accurate results. Quat compounds to which this method has been validated include alkyldimethylbenzylammonium chloride (ADBAC) and didecyldimethylammonium chloride (DDAC) and DDAC equivalents.