Abstract：
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.
摘要：
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），在测定Cd之前进行柱分离以去除海水基质，Cr,Cu,Fe,Pb,Mn,Mo,Ni,U,V,Zn,而As是在10倍稀释的海水样品中直接测量的，在200倍稀释的海水样品中直接测量B。高分辨率电感耦合等离子体质谱(HR-ICPMS)用于元素分析,用双同位素稀释准确测定B，Cd,Cr,Cu,Fe,Pb,Mo,Ni,U,海水NASS-7和CASS-6中的锌，以及砷的标准添加校准，Co,Mn,V.此外，使用标准添加校准用三重四极杆(QQQ)-ICPMS测量所有分析物,以提供NRC的第二组数据。邀请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。参与者采用了各种分析方法，包括柱分离，共沉淀,和简单的稀释耦合到ICPMS检测或流动注射分析耦合到化学发光检测，使用双同位素稀释校准，矩阵匹配外部校准，和标准添加校准。这项研究的结果表明，大多数实验室已经证明了其准确测定海水中痕量金属的测量能力。作为这个比较的结果,对海水CRMsNASS-7和CASS-6中的14个元素分配了认证/参考值和相关的不确定度，适用于验证用于海水分析的方法。
