A UV resonance Raman (UVRR) spectroscopic study on the extractable compounds of Scots pine (Pinus sylvestris) wood Part I: Lipophilic compounds

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: Nuopponen M, Willfor S, Jaaskelainen AS, Sundberg A, Vuorinen T
Publisher: PERGAMON-ELSEVIER SCIENCE LTD
Publication year: 2004
Journal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Journal acronym: SPECTROCHIM ACTA A
Volume number: 60
Issue number: 13
Start page: 2953
End page: 2961
Number of pages: 9
ISSN: 1386-1425


Abstract

The wood resin in Scots pine (Pinus sylvestris) stemwood and branch wood were studied using UV resonance Raman (UVRR) spectroscopy. UVRR spectra of the sapwood and heartwood hexane extracts, solid wood samples and model compounds (six resin acids, three fatty acids, a fatty acid ester, sitosterol and sitosterol acetate) were collected using excitation wavelengths of 229, 244 and 257 run. In addition, visible Raman spectra of the fatty and resin acids were recorded. Resin compositions of heartwood and sapwood hexane extracts were determined using gas chromatography. Raman signals of both conjugated and isolated double bonds of all the model compounds were resonance enhanced by UV excitation. The oleophilic structures showed strong bands in the region of 1660-1630 cm(-1). Distinct structures were enhanced depending on the excitation wavelength. The UVRR spectra of the hexane extracts showed characteristic bands for resin and fatty acids. It was possible to identify certain resin acids from the spectra. UV Raman spectra collected from the solid wood samples containing wood resin showed a band at similar to1650cm(-1) due to unsaturated resin components. The Raman signals from extractives in the resin rich branch wood sample gave even more strongly enhanced signals than the aromatic lignin. (C) 2004 Elsevier B.V. All rights reserved.


Keywords

extractives, fatty acids, pine wood, resin acids, sitosterol, UV Raman spectroscopy

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