Chromatographic methods for the determination of alkylketene dimer in pulp and paper matrices

Abstract

Chromatographic procedures for the determination of alkylketene dimer (AKD) and stearone were evaluated. The best results were obtained when AKD was converted into its ketone form before determination by GC. Bound AKD in paper samples is best removed by digestion of the paper with either hydrochloric acid or sodium carbonate. A separation scheme based on solid-phase extraction was developed for the determination of hydrolysed AKD in deposits from alkaline paper mills. As different AKD emulsions have different chromatographic patterns, it is recommended that standards be prepared from the same AKD that was used in the sizing process. The GC determination of AKD and stearone can be significantly expedited by using Soxtec extraction (rather than Soxhlet extraction) and by employing short capillary GC columns.