Characterization of resin in radiata pine woods, bisulfite pulps and mill pitch samples

Methods for the chromatographic analysis of lipophilic extractives (resin) in radiata pine wood, bisulfite pulp and mill pitch samples are described. The mass of substances extracted from fresh wood samples decreased as the polarity of solvents decreased, in the order methanol > acetone > dichloromethane > hexane. However The amounts of individual lipophilic extractives analysed were not as dependent on extraction solvent. High performance size exclusion chromatography (HPSEC) separated the extracts into four fractions namely triglycerides, steryl esters, sterols and fatty acids, and resin acids. Gas chromatography-mass spectrometry (GC-MS) of trimethylsilyl (TMS) derivatives of the extracts gave good separation of resin acids and fatty acids as their TMS esters, and of sterols as their TMS ethers The pitch sample consisted mainly of salts of fatty acids, with smaller amounts of resin acid salts, sterols and steryl esters, and only trace amounts of triglycerides. It is concluded that the combination of GC-MS and HPSEC is useful for the analysis of radiata pine extractives, allowing the estimation of individual resin and fatty acids and steroids, and total amounts of steryl esters and triglycerides.