Rapid analysis of apolar low molecular weight constituents in wood using high pressure liquid chromatography with evaporative light scattering detection

Abstract

A new high pressure liquid chromatographic method with evaporative light scattering detection was developed for the qualitative and quantitative analysis of apolar, low molecular weight constituents in wood. The wood extractives were obtained by means of a 6 h Soxhlet extraction with acetone. The extract was quantitatively analysed on an end-capped C18 column eluted with a gradient of acetonitrile:water:acetic acid. The crude sample was directly injected following dissolution in acetonitrile:methanol:dichloromethane (60:8:40) and filtration through a 0.45 ?m membrane filter. No other time consuming fractionation or derivatisation steps were required prior to the analysis. The main apolar, low molecular weight constituents of pinewood are free fatty acids, resin acids, sterols and triglycerides. With this method, individual free fatty acids, sterols and triglycerides are well separated. Resin acids, with the exception of dehydroabietic acid, are not separated and co-elute. The method does not require any sample clean-up steps except filtration and it is compatible with other softwood and hardwood wood species