森林土壤中素甲氧基组的同位素分析 (δ13C和 δ2H),以确定和量化素来源
Terry Cox1, Anna Wieland2, Markus Greule2
1Department of Environmental Sciences, University of Basel, Bernoullistrasse 30, 4056 Basel, Switzerland.
The Science of the total environment
|July 26, 2024
概括
在Lignin的基础上.
科学领域:
- 土壤科学 土壤科学
- 生物地质化学生物地质化学
- 有机化学 有机化学
背景情况:
- 土壤有机物 (SOM) 的形成受碳源分配的影响.
- 植物中丰富的红素对SOM至关重要,但其来源尚不清楚.
- 复杂的红素结构阻碍了对其对SOM的贡献的分析.
研究的目的:
- 在对比的土壤类型中调查红素源对SOM的贡献.
- 应用双同位素分析的素甲氧基 (LMeO) 的来源分配.
- 评估红素来源转移对碳循环模型的影响.
主要方法:
- 对LMeO的双同位素分析 (δ13C和δ2H) 的新应用.
- 使用贝叶斯混合模型 (MixSIAR) 来进行源分配.
- 在podzol和stagnosol土壤类型中分析了素来源.
主要成果:
- δ2H LMeO值区分在地面上方/下方的地面红素来源.
- δ13C LMeO 值区分了光合作用和非光合作用组织.
- 叶子垃圾的红素随着降解而减少;根红素占主导地位.
- 波兹罗尔阿赫的地平线积累了地面上方的木质红素.
- 14% (stagnosol) 和11% (podzol) 的散装13C缩归因于LMeO来源的转移.
结论:
- 对LMeO的双同位素分析有效地分配了红素来源.
- 素来源的贡献因土壤类型,降解和深度而异.
- 使用13C丰富的模型可能会高估碳循环,因为素来源的转移.
相关概念视频
03:46Qualitative Analysis
For solutions containing mixtures of different cations, the identity of each cation can be determined by qualitative analysis. This technique involves a series of selective precipitations with different chemical reagents, each reaction producing a characteristic precipitate for a specific group of cations. Metal ions within a group are further separated by varying the pH, heating the mixture to redissolve a precipitate, or adding other reagents to form complex ions.
For instance, group IV...
For instance, group IV...
01:13Mass Spectrometry: Isotope Effect
Most elements exist in nature as a mixture of isotopes. The isotopes differ in weight due to their respective number of neutrons. The molecular weight of a molecule is different depending on the specific isotope of its elements involved. As a result, the mass spectrum of the molecule exhibits peaks from the same fragment at multiple positions. The positions of these mass signals depend on the mass differences between isotopes. Furthermore, the intensity of these signals is dependent on the...