Assessment of pine and spruce wood proportions in pulp production by the analysis of resin acids

Abstract

A convenient method to assess the proportions of pine and spruce wood in pulping processes is described. The method is based on the determination of pimaric acid and sandaracopimaric acid in wood, pulp or water samples by gas chromatography (GC). The ratio of pimaric acid to sandaracopimaric acid is very different in pines and spruces. As the two acids are stereoisomers, their ratio is likely to remain constant during pulping and papermaking regardless of wood storage, process conditions, etc. A change in the ratio of pine to spruce wood will therefore be reflected as a change in the ratio of pimaric acid to sandaracopimaric acid.