Cavity Ring Down Spectrometer (CRDS)

光腔衰荡光谱仪 (CRDS)

• 批准号: 516693059
• 金额: --
• 依托单位: Universität Konstanz
• 依托单位国家: 德国
• 项目类别: Major Research Instrumentation
• 财政年份: 2023
• 资助国家: 德国
• 起止时间: 2022-12-31 至 无数据
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/516693059?language=en
• 关键词: Cavity; Ring; Down; Spectrometer; CRDS

The relatively new technology Cavity Ring Down Spectroscopy (CRDS) enables fast and reliable measurement of absolute concentrations of isotopic 13C- and 12C-CO2, and 13C-C and 12C-CH4, in gas samples. CRDS is superior to conventional methods such as GC isotope-ratio mass spectrometry (GC-IRMS): the instrument is comparatively small, robust and easy to maintain, and it can be deployed also to in situ measurement campaigns in the field. CRDS to detect these gases not only by their isotopic ratio but in their absolute quantities, is essential for two main research applications proposed here: (i) improving the biodegradability of novel polyethylene-like polymers, and (ii) assessing the processes responsible for the distribution and the fluxes of methane in freshwater lakes.In a collaborative project, we are optimizing the microbial degradation of novel, fully recyable, long-chain polyester materials synthesised from renewable resources (plant oil). Complete degradation of plastic by environmental microbial communities is typically monitored via the evolution of CO2. However, to differentiate the CO2 evolved from background activity in complex environmental matrices (e.g. soil, compost), labelling of the polymers with 13C-carbon isotope is the method of choice. At University of Konstanz exists an unprecedented opportunity in that sufficient amounts of 13C labelled long-chain polyesters can be made accessible for biodegradation experiments. CRDS enables us to selectively and very precisely follow the plastic-carbon through the cascade of transformation processes towards the end product 13C CO2 in complex natural matrices. Thereby, we can fine-tune in iterative cycles the frequency of ester-links and side groups breaking up the crystallinity of the polymers, towards a development of novel polymers that combine sufficient material properties and complete biodegradability within few years instead of decades or centuries.Additionally, CRDS enables us to evaluate spatial and temporal distributions and release of the greenhouse gases CO2 and CH4 from freshwater ecosystems such as Lake Constance and other lakes and reservoirs, in unprecedented in-situ studies, e.g., field campaigns on a research ship and when sampling along the water column. This will acquire 13C/12C-CH4 ratios and parent concentrations and thus, allow for distinguishing of CH4 production (anaerobic and aerobic methanogenesis), transport (e.g., diffusive emission) and transformation (e.g., aerobic and anaerobic CH4 oxidation) processes. We thereby will disentangle the origin of the dissolved CH4 in the stratified water column and the oversaturation of CH4 in the oxic water layers of lakes (‘methane paradox’). Overall, CRDS may enable us to resolve several long-standing questions on the CH4 production, transformation, transport and emission phenomena for freshwater lakes to, ultimately, improve climate models.H4

相对较新的光腔衰荡光谱 (CRDS) 技术能够快速、可靠地测量气体样品中同位素 13C- 和 12C-CO2、以及 13C-C 和 12C-CH4 的绝对浓度，优于 CRDS 等传统方法。同位素比质谱 (GC-IRMS)：该仪器相对较小、坚固耐用且易于维护，并且还可以部署到CRDS 不仅可以通过同位素比来检测这些气体，还可以通过其绝对数量来检测这些气体，这对于这里提出的两个主要研究应用至关重要：(i) 提高新型聚乙烯类聚合物的生物降解性，以及 (ii) 评估负责这些气体的过程。淡水湖中甲烷的分布和通量。在一个合作项目中，我们正在优化由可再生资源（植物油）合成的新型、完全可回收的长链聚酯材料的微生物降解。环境微生物群落对塑料的影响通常通过 CO2 的演变来监测，但是，为了区分复杂环境基质（例如土壤、堆肥）中背景活动演变的 CO2，可以选择用 13C-碳同位素标记聚合物。康斯坦茨大学存在一个前所未有的机会，可以为生物降解实验提供足够量的 13C 标记的长链聚酯，使我们能够有选择地、非常精确地遵循。通过在复杂的天然基质中向最终产品 13C CO2 进行级联转化过程，我们可以在迭代循环中微调破坏聚合物结晶度的酯键和侧基的频率，从而实现塑料-碳的发展。新型聚合物在几年而不是几十年或几个世纪内结合了足够的材料特性和完全的生物降解性。此外，CRDS 使我们能够评估温室气体 CO2 和 CH4 的空间和时间分布以及释放从康斯坦茨湖和其他湖泊和水库等淡水生态系统中，在前所未有的原位研究中，例如在研究船上进行野外活动以及沿水柱采样时，这将获得 13C/12C-CH4 比率和母体浓度。 ，允许区分 CH4 生产（厌氧和好氧产甲烷）、运输（例如扩散排放）和转化（例如需氧和需氧）因此，我们将解开分层水体中溶解的 CH4 的来源和湖泊含氧水层中 CH4 的过饱和（“甲烷悖论”）。总体而言，CRDS 可以帮助我们解决几个长期难题。 -关于淡水湖的 CH4 生产、转化、运输和排放现象的悬而未决的问题，最终改善气候模型。H4