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

相对新的技术腔环向下光谱（CRDS）可以在气体样品中快速可靠地测量同位素13C和12C-CO2的绝对浓度，以及13C-C和12C-CH4。 CRD优于常规方法，例如GC同位素比率质谱法（GC-IRMS）：该仪器相对较小，健壮且易于维护，并且可以将其部署到现场测量运动中。 CRD不仅通过其同位素比，而且在其绝对数量中检测这些气体，对于此处提出的两个主要研究应用至关重要：（i）提高新型聚乙烯聚合物的生物降解性，以及（ii）评估造成近期甲烷的近期定义，我们的近期定义，我们是在近期的近期定义，我们是在近期繁殖的，我们是近期的，我们是近期的。从可再生资源（植物油）合成的聚酯材料。环境微生物群落对塑料的完整定义通常通过CO2的进化来监测。但是，要区分复杂环境物质（例如土壤，堆肥）中的背景活动的二氧化碳，用13c-碳同位素对聚合物的标记是选择的方法。在康斯坦茨大学存在一个前所未有的机会，可以使足够数量的13C标记的长链聚植物可用于生物降解实验。 CRDS使我们能够通过层叠过程在复杂的天然材料中的最终产物13C CO2进行选择性，非常精确地跟随塑料碳。因此，我们可以在迭代循环中微调酯链接和侧群的频率，并分解聚合物的结晶度，以开发新型聚合物的发展，这些聚合物结合了足够的材料特性和几年或几个世纪之内，而不是在数十年或几个世纪内进行完整的生物降解性。作为康斯坦斯湖以及其他湖泊和水库，在前所未有的原位研究中，例如，研究船上的现场运动以及沿着水柱进行采样时。这将获取13C/12C-CH4的比率和母体浓度，因此可以区分CH4产生（厌氧和有氧甲烷生成），转运（例如，分化的发射）和转化（例如有氧和厌氧和厌氧CH4氧化）过程。因此，我们将在分层的水柱中解散溶解的CH4的起源，并在湖泊（“甲烷悖论”）（“甲烷悖论”）中的CH4过度饱和。总体而言，CRD可以使我们能够解决有关CH4生产，转型，运输和排放现象的几个长期问题，以最终改善气候模型。H4