Analysis of δ18O in tree rings: Wood-cellulose comparison and method dependent sensitivity

Borella, Silvio; Leuenberger, Markus; Saurer, Matthias (1999). Analysis of δ18O in tree rings: Wood-cellulose comparison and method dependent sensitivity. Journal of Geophysical Research: Atmospheres, 104(D16), pp. 19267-19273. American Geophysical Union 10.1029/1999JD900298

Preview

Text borella99jgr.pdf - Published Version Available under License Publisher holds Copyright. Download (856kB) | Preview

During recent years, new on-line methods in mass spectrometry have been developed for measuring δ18O in organic material. They allow a much higher sample throughput than off-line methods with the result that sample preparation becomes the time-limiting factor. Therefore we tested whether analysis of tree ring samples can be made on whole wood instead of pure cellulose, which until now was commonly used in almost all 18O tree ring studies. Measurements with an on-line method based on pyrolysis in an elemental analyzer show that the tree ring δ18O time series of wood and cellulose from an oak of the Swiss “Mittelland” are similar (r2 = 0.65). However, there are significant differences, and some climatic information may be lost if bulk wood is analyzed instead of cellulose. This can partly be balanced by an increased sample throughput, resulting in the averaging of more data. Further, we improved an off-line method (pyrolysis in a nickel tube followed by catalytic CO to CO2 conversion on nickel powder) by adding a CO2 trap to enhance the CO to CO2 conversion. The best reproducibility associated with this method is better than 0.1‰. We also found a strong memory effect linked with this method, causing a dampening of the signal of 30–40%. Therefore published climatic interpretation of δ18O data measured using similar methods may require revision.

Interest & Impact

Downloads

77 since deposited on 22 Sep 2021
27 in the past 12 months

Citations

5 Citations in Web of Science ®
6 Citations in Scopus

Search

in Google Scholar™

Services

Actions (login required)

Edit item

Actions (login required)

Edit item