ASSESSMENT OF CARBOXYL GROUPS OF SOME CANADIAN ARCTIC FOSSIL WOODS TOEVALUATE THEIR DEGRADATION

Five fossil woods from the Canadian Arctic, previously studied with st andard methods of chemical analysis, were examined with respect to dif ferent forms of carboxyl groups (protonated, carboxylate and esters) a nd compared with those of the reference woods. The fossil wood from Re solute, Cornwallis Island, anatomically identified as white pine, and the sample GH28, tentatively identified as larch or redwood, exhibited only small differences with respect to the forms and amounts of carbo xyls in the reference species. Fossil GH61, identified as Douglas fir, showed all the original forms, although in amounts slightly larger th an the reference Douglas fir. The two unidentified fossils had undergo ne thorough degradation. In these last samples, as in several European fossil woods, the carboxyl groups seem to derive from oxidized struct ures of degraded lignin. (C) 1997 Published by Elsevier Science Ltd. A ll rights reserved.