Abstract The analytical procedures for the reference measurements of cadmium and lead concentrations in four candidates for new environmental certified reference materials were developed. Cadmium and lead content was determined in bottom sediment (M-2 BotSed), Baltic herring tissue (M-3 HerTis), cormorant tissue (M-4 CormTis) and codfish tissue (M-5 CodTis). The measurements were carried out with the use of a direct isotope dilution inductively coupled plasma mass spectrometry (ID ICP-MS). The isotope dilution approach and the combined uncertainty of results are based on the mathematical equations as from definition of a primary method of measurement. All factors influencing the final results included: the procedural blank, the moisture content in the materials, the factors affecting the blend ratio measurements (instrumental background, spectral interferences, dead time, mass discrimination effects and the repeatability of measured isotopic ratios) as well as the isotopic equilibrium were systematically investigated and included in the uncertainty budget. The content of cadmium in candidates for new environmental reference materials, after correction for moisture contents, matrix separation on ion-exchange resin AG1-X8 of the blended samples and after using for the ICP-MS measurements ratio of pair of isotopes n(110Cd)/n(111Cd) was found to be: (2.18 ± 0.06) μg g−1 in M-2 BotSed, (337 ± 2) ng g−1 in HerTis, (16.4 ± 0.6) ng g−1 in CormTis) and (2.7 ± 0.4) ng g−1 in CodTis, respectively. The content of lead in candidates for new environmental reference materials, after correction for moisture contents, matrix separation on ion-exchange resin AG1-X8 of the blended samples and after using for the ICP-MS measurements ratio of pair of isotopes n(208Pb)/n(207Pb) was found to be: (108 ± 5) ng g−1 in M-3 HerTis, (2.34 ± 0.12) μg g−1 in M-4 CormTis and (43 ± 2) ng g−1 in M-5 CodTis, respectively. The Cd and Pb contents determined in this work were used as a contribution of the Faculty of Chemistry, Biological and Chemical Research Centre University of Warsaw in the characterisation of the abovementioned candidates for new certified reference materials in the frame of the Inter-Laboratory Comparison, organized by the Institute Nuclear Chemistry and Technology (Warsaw, Poland). The obtained excellent agreement within uncertainties with the reference values further validated the methods developed in this study.

中文翻译：

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通过同位素稀释电感耦合等离子体质谱法对候选新环境认证材料中的镉和铅含量进行参考测量

摘要 开发了四种候选新环境认证参考材料中镉和铅浓度参考测量的分析程序。在底部沉积物 (M-2 BotSed)、波罗的海鲱鱼组织 (M-3 HerTis)、鸬鹚组织 (M-4 CormTis) 和鳕鱼组织 (M-5 CodTis) 中测定了镉和铅含量。使用直接同位素稀释电感耦合等离子体质谱法 (ID ICP-MS) 进行测量。同位素稀释方法和结果的组合不确定度基于主要测量方法定义中的数学方程。影响最终结果的所有因素包括：程序空白、材料中的水分含量、影响混合比测量的因素（仪器背景、谱干扰、死时间、质量区分效应和测得的同位素比率的可重复性）以及同位素平衡被系统地研究并包括在不确定性预算中。新环境参考物质候选物中镉的含量，经过水分校正，混合样品的离子交换树脂 AG1-X8 上的基质分离和用于 ICP-MS 测量后同位素对 n(110Cd) 的比率/n(111Cd) 被发现是： (2.18 ± 0.06) μg g-1 在 M-2 BotSed 中，(337 ± 2) ng g-1 在 HerTis，(16.4 ± 0.6) ng g-1 在 CormTis) 和(2.7 ± 0.4) ng g-1 在 CodTis 中，分别。新环境标准物质候选物的铅含量，经水分校正后，混合样品的离子交换树脂 AG1-X8 上的基质分离以及用于 ICP-MS 测量后发现同位素对 n(208Pb)/n(207Pb) 的比率为：(108 ± 5) ng g− M-3 HerTis 中为 1，M-4 CormTis 中为 (2.34 ± 0.12) μg g-1，M-5 CodTis 中分别为 (43 ± 2) ng g-1。在这项工作中确定的 Cd 和 Pb 含量被用作华沙大学化学学院生物和化学研究中心在实验室间比较框架内表征上述新认证参考材料候选物的贡献，由核化学与技术研究所（波兰华沙）组织。在不确定性范围内与参考值获得的极好一致性进一步验证了本研究中开发的方法。