Methoxyphenols from burning of Scandinavian forest plant materials

Semivolatile compounds in smoke from gram-scare incomplete burning of plant materials were assessed by gas chromatography and mass spectrometry. Gas s yringe sampling was shown to be adequate by comparison with adsorbent sampl ing. Methoxyphenols as well as 1,6-anhydroglucose were released in amounts as large as 10 mg kg(-1) of dry biomass at 90% combustion efficiency. Wood, twigs, bark and needles from the conifers Norway spruce and Scots pine emi tted 12 reported 2-methoxyphenols in similar proportions. Grass, heather an d birchwood released the same 2-methoxyphenols but also the corresponding 2 ,6-dimethoxyphenols which are characteristic of angiosperms. The methoxyphe nols are formed from lignin and differ in structure by the group in para po sition relative to the phenolic OH group. Prominent phenols were those with trans-1-propenyl and ethenyl groups in that position. Vanillin, 4-hydroxy- 3-methoxybenzaldehyde, was a prominent carbonyl compound from the conifer m aterials. (C) 2000 Elsevier Science Ltd. All rights reserved.