Multiflow system for stable isotope analyses

液态、气态和固态化合物中碳和氧的稳定同位素是生物和地球化学过程的示踪剂，用于许多学科领域的研究。此处要求的设备（MultiFlow Geo）是一个气体提取系统，与同位素比率质谱仪相结合，用于从其他气体中分离CO2，并用于测量低丰度碳和氧同位素。该设备包括一个自动进样器，可实现高通量和无人值守的连续分析。它还包括一个自动酸消化装置，用于从碳酸盐中回收CO2。与目前手动操作的反应容器相比，该仪器优化了操作并降低了测量不确定性，允许样品量从小于10微克到毫克，因此可以测量有孔虫（单细胞微生物）的单壳以及牙齿或石笋的季节性生长层。自动进样器配有温控托盘和气体分离系统，每3分钟可处理一个样品。补充工具包将允许分析：1）用于水文调查的水中氢和氧同位素，2）用于碳循环研究的溶解无机碳的碳同位素，3）用于生物医学应用的呼吸CO2中的碳和氧同位素。 所要求的仪器将取代22年前购买的现有介绍系统（MicroGas），该系统在过去15年中为加拿大25名大学教授和40名学生进行了23000多次分析。这个旧系统不能配置为自动注入酸，也不能冲洗反应瓶，也不能运行微量样品。拟议的仪器除了大大提高目前的处理量外，还将允许进行大量新的实验和研究项目。它将补充Geotop地球系统科学研究中心的世界级轻稳定同位素基础设施，该研究中心已为培训130多名学生做出了贡献，为私营部门提供了分析支持。 申请方和共同申请方将利用该仪器开展的主要研究项目侧重于：（a）北冰洋海冰覆盖的气候历史和变化;（B）调节地球气候的长期冰-海-大气相互作用;（c）哺乳动物牙齿化石和洞穴石笋等地质档案中的季节性气候差异和极端情况; d）史前原始人饮食与气候的关系的重建，e）海洋酸化，以及f）地下水资源的更新和质量。除了本申请的共同申请者外，私营部门和学术部门的广大用户也将使用这些设备。 每年约有20名学生、若干名博士后和访问学者将接受使用气体提取系统进行稳定同位素测量的培训。

The stable isotopes of carbon and oxygen in liquid, gas and solid compounds are tracers of biological and geochemical processes that are used for investigations in many disciplinary fields. The equipment (MultiFlow Geo) requested here is a gas extraction system to be coupled with an isotopic ratio mass spectrometer for the separation of CO2 from other gases and its introduction for measurements of low abundance carbon and oxygen isotopes. The equipment includes an autosampler that enables high throughput and unattended continuous analyses. It also includes an automated acid digestion unit for the recovery of CO2 from carbonates. The instrument optimizes operations and reduces measurement uncertainty compared to the current manually operated reaction vessels, allowing for sample sizes from less than 10 micrograms to milligrams and, thus, measurements of single shells of foraminifer (unicellular microorganism) as well as seasonal growth layers of teeth or stalagmites. The autosampler with temperature-controlled tray and gas separation system can process one sample every 3 minutes. Complementary kits will allow analyses of 1) hydrogen and oxygen isotopes in water for hydrology investigations, 2) carbon isotopes of dissolved inorganic carbon for studies of the carbon cycle, and 3) carbon and oxygen isotopes in breath CO2, for biomedical applications. The requested instrument will replace the current introduction system (MicroGas), acquired 22 years ago, that has generated more than 23 000 analyses over the last 15 years, for 25 university professors across Canada and 40 of their students. This old system cannot be configured to automatically inject acid nor flush reaction vials, nor run micro-samples. The proposed instrument would permit a large array of new experiments and research projects in addition to significantly enhancing the current throughput. It will complement the world-class light stable isotopes infrastructure of the Geotop research center in Earth system science, which has contributed to the training of more than 130 students, adding analytical support for the private sector. The main research projects of the applicant and co-applicants to be conducted with the instrument focus on a) the climate history and variations of sea ice cover in the Arctic Ocean, b) long-term ice-ocean-atmosphere interactions regulating the Earth climate, c) the seasonal climate contrasts and extremes in geological archives such as teeth of fossil mammals and cave stalagmites, d) the reconstruction of diets of prehistorical hominids in relation with climate, e) ocean acidification, and f) the renewal and quality of groundwater resources. In addition to the co-applicants of the present request, the equipment will be used by a large community of users from the private and academic sectors. On a yearly basis, about 20 students, several postdoctoral and visiting scholars will be trained for stable isotope measurements using the gas extraction system.