Beryllium isotopes have emerged as a quantitative tracer of continental weathering, but accurate and precise determination of the cosmogenic ¹⁰Be and stable ⁹Be in seawater is challenging, because seawater contains high concentrations of matrix elements but extremely low concentrations of ⁹Be and ¹⁰Be. In this study, we develop a new, time-efficient procedure for the simultaneous preconcentration of ⁹Be and ¹⁰Be from (coastal) seawater based on the iron co-precipitation method. The concentrations of ⁹Be, ¹⁰Be, and the resulting ¹⁰Be/⁹Be ratio for Changjiang Estuary water derived from the new procedure agree well with those obtained from the conventional procedure requiring separate preconcentration for ⁹Be and ¹⁰Be determinations. By avoiding the separate preconcentration, our newly developed procedure contributes toward more time-efficient handling of samples, less sample cross-contamination, and a more reliable ¹⁰Be/⁹Be ratio. Prior to this, we validated the iron co-precipitation method using artificial seawater and natural water samples from the Amazon Estuary regarding: (1) the “matrix effect” for Be analysis, (2) its extraction efficiency for pg g⁻¹ levels Be in the presence and absence of organic matter, and (3) the data comparability with another preconcentration method. We calculated that for the determination of ⁹Be and ¹⁰Be in most open ocean seawater with typical ¹⁰Be concentrations of > 500 atoms g⁻¹, good precisions (< 5%) can be achieved using less than 3 liters of seawater compared to more than 20 liters routinely used previously. Even for coastal seawater with extremely low ¹⁰Be concentration (e.g., 100 atoms g⁻¹), we estimate a maximum amount of 10 liters to be adequate.

中文翻译：

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同时富集 9Be 和宇宙源 10Be，用于测定（沿海）海水中的 10Be/9Be 比率

铍同位素已成为大陆风化的定量示踪剂，但精确测定海水中的宇宙成因¹⁰ Be 和稳定^{9 Be 具有挑战性，因为海水含有高浓度的基质元素，但9} Be 和¹⁰ Be浓度极低。在这项研究中，我们开发了一种新的、省时的程序，用于基于铁共沉淀法从（沿海）海水中同时富集⁹ Be 和^{10 Be。}从新程序中获得的长江口水的⁹ Be、¹⁰ Be浓度以及由此产生的¹⁰ Be/ ^{9 Be 比率与从需要单独预浓缩9} Be 和¹⁰ Be 测定的传统程序中获得的结果非常吻合。通过避免单独预浓缩，我们新开发的程序有助于更高效地处理样品、减少样品交叉污染以及更可靠的¹⁰ Be/ ⁹ Be 比率。在此之前，我们使用来自亚马逊河口的人工海水和天然水样验证了铁共沉淀方法：（1）Be 分析的“基质效应”，（2）其对 pg g ⁻¹水平 Be的提取效率在存在和不存在有机物的情况下，以及（3）与另一种预浓缩方法的数据可比性。我们计算出，对于大多数开放海洋海水中⁹ Be 和¹⁰ Be的测定（典型¹⁰ Be 浓度 > 500 原子 g ⁻¹），与更多的海水相比，使用不到 3 升的海水即可实现良好的精度 (< 5%)。超过以前常规使用的 20 升。^{即使对于10} Be 浓度极低（例如 100 个原子 g ^-1）的沿海海水，我们估计最大量 10 升就足够了。