Analysis of (cid:127)180 in tree rings: Wood-cellulose comparison and method dependent sensitivity
Analysis of (cid:127)180 in tree rings: Wood-cellulose comparison and method dependent sensitivity
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树木年轮中 (cid:127)180 的分析：木材纤维素比较和方法依赖性灵敏度
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
Markus Leuenberger
中科院分区：
文献类型：
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作者：
Silvio Borella;Markus Leuenberger
.近年来，发展了一种新的质谱在线测定有机物中B（cid：127）SO的方法。它们允许比离线方法高得多的样品通量，结果样品制备成为时间限制因素。因此，我们测试了树木年轮样本的分析是否可以在整个木材上进行，而不是纯纤维素，到目前为止，这是普遍使用的几乎所有（cid：127）80树木年轮研究。在元素分析仪中基于热解的在线方法的测量表明，从瑞士中部地区的橡树的木材和纤维素的树轮B（cid：127）80时间序列是相似的（r2 = 0.65）。然而，有显着的差异，一些气候信息可能会丢失，如果分析散装木材，而不是纤维素。这可以通过增加样品吞吐量来部分平衡，从而平均更多数据。此外，我们通过添加CO2捕集器来提高CO到CO2的转化率，从而改进了离线方法（在镍管中热解，然后在镍粉上催化CO到CO2的转化）。与该方法相关的最佳再现性优于0.1%。我们还发现了与这种方法相关的强烈记忆效应，导致信号衰减30- 40%。因此，使用类似方法测量的B（cid：127）80数据的已发表气候解释可能需要修订。
. During recent years, new on-line methods in mass spectrometry have been developed for measuring b(cid:127)SO 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 (cid:127)80 tree ring studies. Measurements with an on-line method based on pyrolysis in an elemental analyzer show that the tree ring b(cid:127)80 time series of wood and cellulose from an oak of the Swiss Mittelland are similar (r 2 = 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%o. 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 b(cid:127)80 data measured using similar methods may require revision.