The quality control of oceanic carbon dioxide measurements: preparation and distribution of reference materials

该项目的目标是继续为海洋二氧化碳测量的质量控制提供一种机制，特别是那些作为国际全球计划一部分的测量。这将有助于确保这些测量虽然在不同的实验室在不同的时间进行，但具有可比性和准确性，并将成为设计全球海洋观测系统（如拟议的全球海洋酸化观测网）的一个重要因素，并在海洋酸化测量的质量控制方面发挥重要作用。为了实现这一目标，斯克里普斯实验室将为海水中海洋二氧化碳系统的以下参数制备和认证标准物质：总溶解无机碳、总碱度和氢离子浓度、ph。总溶解无机碳和总碱度的标准物质将以天然海水为基础，经过灭菌、装瓶，并使用适当的参比方法对这些参数进行分析。pH值的参考材料将基于合成海水中的Tris缓冲液，其pH值与使用经典Harned细胞的测量结果直接相关。此外，实验室将分发校准的酸滴定剂用于碱度测量。向国际社会提供参考材料有助于提高世界各地海洋碳数据的总体质量，无论是用于海洋碳分布的实地研究，还是用于与海洋酸化有关的研究。因此，这项努力是美国对该领域研究基础设施的重大贡献。

The goal of this project is to continue to provide a mechanism for the quality control of ocean carbon dioxide measurements, in particular those that are made as part of international global programs. This will help to ensure that such measurements are comparable and accurate although made in different laboratories at different times, and will be an important factor in the design of a Global Ocean Observing System such as the proposed Global Ocean Acidification Observation Network, as well as playing a significant role in the quality control of ocean acidification measurements. To achieve this goal, the Scripps laboratory will prepare and certify reference materials for the following parameters of the oceanic carbon dioxide system in seawater: total dissolved inorganic carbon, total alkalinity, and hydrogen ion concentration, pH. The reference materials for total dissolved inorganic carbon and for total alkalinity will be based on natural seawater, sterilized, bottled, and analyzed using appropriate reference methods for these parameters. Reference materials for pH will be based on Tris buffers in synthetic seawater whose pH is directly related to measurements using classical Harned cells. In addition, the laboratory will distribute calibrated acid titrant for alkalinity measurements. The provision of reference materials to the international community helps to improve the overall quality of oceanic carbon data around the world both for field studies of the distribution of oceanic carbon, as well as for studies related to ocean acidification. Thus this effort is a significant US contribution to research infrastructure in this field.