A GC-MS system for the analysis of biomarkers and petroleum-derived contaminants in natural systems

要求Agilent GC-MS代替16-y.o.该仪器对我们的研究至关重要，但已于4年前停止运行。该仪器是实验室的主力，在一系列研究中利用有机生物标志物来解释有机物质的来源、加工和汇，以及石油衍生污染物的来源和归宿。将使用所要求的仪器解决的主要科学问题是：（1）自世纪初以来，河口最大浑浊度和缺氧区的水柱和沉积物中有机物动态的变化是什么，以及物理和生物化学过程在多大程度上导致散装陆地OM与其分子和同位素特征之间的脱钩？(2)在海洋和湖泊沉积物中，与铁氧化物特别相关的有机物的分子水平组成是什么？(3)在圣劳伦斯水道过境的主要石油衍生污染物的分子和同位素指纹是什么，它们在分散和运输过程中如何变化？(4)在地下水和海水中发现的微量低分子量水热的浓度和性质是什么？此外，作为正在进行的气候变暖条件下高纬度土壤和湿地中碳储存库稳定性研究的一部分，我们将（5）使用分子生物标志物的分布和同位素组成追踪从陆地到水生生态系统的碳运输的分子尺度过程;（6）开发古细菌和细菌脂质的同位素分析，作为甲烷循环的示踪剂。我们估计，作为这些项目的一部分，每年进行的GC-MS分析数量将超过1000次，在基础和社会（应用）层面都有重大成果。

An Agilent GC-MS is requested to replace a 16-y.o. instrument that is critical to our research and that stopped functioning 4 years ago. The instrument is the workhorse of the laboratory and is exploited in a range of studies making use of organic biomarkers to decipher organic matter sources, processing and sinks, as well as petroleum-derived contamination sources and fate. The main scientific questions that will be addressed using the requested instrument are: (1) What are the changes in organic matter dynamics in the water column and sediments of estuarine maximum turbidity and hypoxic zones since the beginning of the century, and to what extent physical and biochemical processes lead to the decoupling between bulk terrestrial OM and its molecular and isotopic signatures? (2) What is the molecular-level composition of organic matter specifically associated with iron oxides in marine and lacustrine sediments? (3) What are the molecular and isotopic fingerprints of the major petroleum-derived contaminants transiting in the St. Lawrence waterways, and how do they change during dispersion and transport? (4) What are the concentration and nature of the LMWHC found at trace levels in ground and sea water? In addition, as part of on-going work on the stability of carbon storage reservoirs in high-latitude soils and wetlands under a warming climate, we will (5) Trace molecular scale processes of carbon transport from terrestrial to aquatic ecosystems using the distribution and isotopic composition of molecular biomarkers; and (6) Develop isotopic analyses of archaeal and bacterial lipids as tracers of methane cycling. We estimate that the number of GC-MS analyses carried out as part of these projects will be >1000 per year, with significant outcomes both at the fundamental and societal (applied) levels.