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 µm 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. Copyright © 2000 John Wiley & Sons, Ltd.

TG/MS, Py-GC/MS and THM-GC/MS study of the composition and thermal behavior of extractive components of Robinia pseudoacacia

“…The amounts of phenolic (e.g. 21) and carbohydrate (20) compounds are also considerably smaller than in the acetone or ethanol extracts. The composition of the steroid fraction is significantly different from that of the acetone or ethanol extracts.…”

“…In the latter case, they may be precursors or intermediates of lignin biosynthesis. Some carbohydrate derivatives (6,7,20) can also be identified. These compounds may be formed as a result of the decomposition of phenolic glycosides [43].…”

“…are taxonomically very important [12]. Owing to the large complexity of extracts, some of the papers focus only on the analysis of a given compound group of extractives [19][20][21].…”

Analysis of phytosterols in foods

“…Phytosterols in plant tissues and seed oils can be isolated by solvent extraction with chloroform-methanol [61], chloroform-methanol-water [62,63], hexane [64][65][66], methylene chloride [67,68] or acetone [69] followed by alkaline hydrolysis and chromatographic purification to obtain enriched total sterols.…”

Superheated water extraction of cholesterol from solid food

“…The official procedure for determination of the total cholesterol-involving free and sterified cholesterol-consists of saponification of the sample with alcoholic potassium hydroxide, extraction of unsaponifiable matter into an organic solvent, evaporation of the extract to dryness and redissolution of the residue in the suitable solvent [11]. Techniques applied for sterol determination in different fields include spectrophotometry [12,13], gravimetry [14], amperometric biosensors [15,16], gas chromatography [17,18,19,20], high-performance liquid chromatography [21,22,23] and mass spectrometry [24,25]. Enzymic procedures have been used either to carry out a previous enzymic hydrolysis of cholesterol esters [26] or for derivatisation [27,28].…”