Certification of trace metals in seawater certified reference materials (CRMs) NASS-7 and CASS-6 is described. At the National Research Council Canada (NRC), column separation was performed to remove the seawater matrix prior to the determination of Cd, Cr, Cu, Fe, Pb, Mn, Mo, Ni, U, V, and Zn, whereas As was directly measured in 10-fold diluted seawater samples, and B was directly measured in 200-fold diluted seawater samples. High-resolution inductively coupled plasma mass spectrometry (HR-ICPMS) was used for elemental analyses, with double isotope dilution for the accurate determination of B, Cd, Cr, Cu, Fe, Pb, Mo, Ni, U, and Zn in seawater NASS-7 and CASS-6, and standard addition calibration for As, Co, Mn, and V. In addition, all analytes were measured using standard addition calibration with triple quadrupole (QQQ)-ICPMS to provide a second set of data at NRC. Expert laboratories worldwide were invited to contribute data to the certification of trace metals in NASS-7 and CASS-6. Various analytical methods were employed by participants including column separation, co-precipitation, and simple dilution coupled to ICPMS detection or flow injection analysis coupled to chemiluminescence detection, with use of double isotope dilution calibration, matrix matching external calibration, and standard addition calibration. Results presented in this study show that majority of laboratories have demonstrated their measurement capabilities for the accurate determination of trace metals in seawater. As a result of this comparison, certified/reference values and associated uncertainties were assigned for 14 elements in seawater CRMs NASS-7 and CASS-6, suitable for the validation of methods used for seawater analysis.

中文翻译：

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实验室间研究，以对海水认证参考物质NASS-7和CASS-6中的痕量元素进行认证

描述了海水认证参考材料（CRM）NASS-7和CASS-6中痕量金属的认证。在加拿大国家研究委员会（NRC）中，在确定Cd，Cr，Cu，Fe，Pb，Mn，Mo，Ni，U，V和Zn之前，先进行柱分离以除去海水基质，而As则为直接在10倍稀释海水样品中直接测量，而B在200倍稀释海水样品中直接测量。使用高分辨率电感耦合等离子体质谱（HR-ICPMS）进行元素分析，并采用双同位素稀释法精确测定海水中的B，Cd，Cr，Cu，Fe，Pb，Mo，Ni，U和Zn NASS-7和CASS-6，以及As，Co，Mn和V的标准添加校准。此外，使用三重四极杆（QQQ）-ICPMS进行标准加标校准，对所有分析物进行了测量，从而在NRC上提供了第二组数据。邀请了世界各地的专家实验室为NASS-7和CASS-6中的痕量金属认证提供数据。参与者采用了多种分析方法，包括柱分离，共沉淀，与ICPMS检测耦合的简单稀释或与化学发光检测耦合的流动注射分析，以及双重同位素稀释校准，基质匹配外部校准和标准添加校准。这项研究提出的结果表明，大多数实验室已经证明了它们的测量能力，可以准确测定海水中的痕量金属。作为比较的结果，