Pure standards of archaeal and bacterial GDGTs for the oceanographic community

在环境中持续存在的各种化合物可用作海洋系统中各种过程的示踪剂，这些过程既发生在最近的过去，也可用于追踪古时间尺度上的变化。 近年来，古细菌和细菌的甘油-二烷基-甘油四醚（GDGT）脂质作为古海洋学和海洋地球化学的替代物引起了人们的兴趣，这类研究一直是最近的研究领域。然而，有必要限制和地面实况的测量，以验证不同的研究小组正在进行的地球化学解释。准确的纯化学标准品对于此类验证至关重要。目前的方法涉及定期校准合成标准品对已知量的纯的，真实的GDGT。然而，由于很少有实验室能够获得真实的GDGT，因此在古代用研究中缺乏严格的校准。 因此，来自哈佛大学的研究人员提出产生纯GDGT以满足这一需求。这项研究的目标是从沉积物中提取这些脂质，纯化单个化合物，并创建可用于定量和放射性碳工作的参考标准。由于GDGT作为示踪剂的科学普及，研究人员的目标是使整个项目向社区“开放访问”。生成后，实验室可以使用这些标准品通过仪器校准检查其制备方法和/或分析方法。此外，这些材料可以作为同位素参考材料，类似于其他机构提供的材料。这项研究的更广泛的影响涉及到拟议的标准将提供给研究界的服务。此外，本科生，研究生和高中生将受益于项目期间的培训机会。

A variety of chemical compounds that persist in the environment can be used as tracers of a variety of processes in ocean systems, both those occurring in the recent past, as well as being used to trace changes over paleo timescales. There has been recent interest in using archaeal and bacterial glycerol-dialkyl-glycerol tetraether (GDGT) lipids as proxies in paleoceanography and biogeochemistry, and such studies have been an area of recent research. However, there is a need to constrain and ground-truth the measurements in order to validate the biogeochemical interpretations being made by the various research groups. Accurate pure chemical standards are critical for such validation. Current methods involve calibrating a synthetic standard regularly against a known quantity of a pure, authentic GDGT. However, as very few labs have access to the authentic GDGT's, there is a lack of strict calibration in paleoproxy studies. Therefore, researchers from Harvard University have proposed to generate pure GDGT's to meet this need. The goal of this research is to extract these lipids from sediments, purify the individual compounds, and create reference standards that can be used in quantitative and radiocarbon work. Due to the scientific popularity of GDGT's as tracers, it is the researchers' goal to make the entire project "open access" to the community. When generated, laboratories can potentially use these standards to check their preparation methods and/or analytical methods through instrument calibration. Additionally, these materials can serve as isotope reference materials, similar to those available from other institutions. The broader impacts of this research relate to the service that the proposed standards will provide to the research community. In addition, undergraduate, graduate, and high school students will benefit from training opportunities during the project.