State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan 430074, P. R. China.
State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074, P. R. China.
Anal Methods. 2022 Jul 21;14(28):2782-2792. doi: 10.1039/d2ay00559j.
Multi-isotope systems have shown great application potential in tracing geological and environmental processes. In order to obtain the isotopic composition of multiple elements of interest, the common protocol is to separate each element from the matrix by independent procedures, which has some limitations, including poor efficiency, being time-consuming, requiring large samples and being unsuitable for rare samples (, meteorite, lunar soil and atmospheric aerosol samples). In this study, we present an integrated and optimized one-step method to separate Cu, Fe, Zn and Cd from complex matrix elements using the AG MP-1M anion exchange resin. By experimentally optimizing the resin volume, eluent concentration and eluent amount, these target elements can be effectively separated from the matrix elements, such as Cu separation from Ti and Co, Zn separation from Fe and Cd, and Cd separation from Sn. The recoveries of Cu, Fe, Zn and Cd were 100.1 ± 0.8% (2SD, = 3), 99.8 ± 0.7% (2SD, = 3), 100 ± 0.8% (2SD, = 3) and 99 ± 1% (2SD, = 3), respectively. Moreover, the resolution () between the elements of interest and interfering elements was in the range of 1.8-28.1. The process blanks of Cu, Fe, Zn and Cd were 1-1.6 ng, 62-70 ng, 2.1-3 ng and 66-74 pg, respectively. The obtained isotope ratios for the standard reference materials agreed well with the published values. Meanwhile, we have reported the Cu, Fe and Zn isotope ratios of six soil and sediment standard reference materials, namely NIST 2711a, GSS-1, GSD-5a, GSD-7a, GSD-12 and GSD-23, for the first time. These new data can be used for the intercalibration and quality control of soils and sediments in other laboratories. The one-step separation of Cu, Fe, Zn and Cd shows obvious economic and efficiency advantages, making it suitable for the simultaneous separation of multiple elements of interest in geological samples.
多同位素体系在示踪地质和环境过程方面具有巨大的应用潜力。为了获得感兴趣的多种元素的同位素组成，通常采用独立的程序从基体中分离每个元素，这种方法存在一些局限性，例如效率低下、耗时、需要大量样品以及不适用于稀有样品（例如陨石、月球土壤和大气气溶胶样品）。在本研究中，我们提出了一种综合优化的一步法，使用 AG MP-1M 阴离子交换树脂从复杂基体元素中分离 Cu、Fe、Zn 和 Cd。通过实验优化树脂体积、洗脱液浓度和洗脱液量，可以有效地将这些目标元素与基体元素（如 Ti 和 Co 中的 Cu、Fe 和 Cd 中的 Zn、Sn 中的 Cd）分离。Cu、Fe、Zn 和 Cd 的回收率分别为 100.1 ± 0.8%（2SD，n = 3）、99.8 ± 0.7%（2SD，n = 3）、100 ± 0.8%（2SD，n = 3）和 99 ± 1%（2SD，n = 3）。此外，感兴趣元素与干扰元素之间的分辨率（）在 1.8-28.1 之间。Cu、Fe、Zn 和 Cd 的过程空白分别为 1-1.6 ng、62-70 ng、2.1-3 ng 和 66-74 pg。标准参考物质的获得同位素比值与已发表值吻合良好。同时，我们首次报道了 NIST 2711a、GSS-1、GSD-5a、GSD-7a、GSD-12 和 GSD-23 六种土壤和沉积物标准参考物质的 Cu、Fe 和 Zn 同位素比值。这些新数据可用于其他实验室土壤和沉积物的相互校准和质量控制。Cu、Fe、Zn 和 Cd 的一步分离具有明显的经济和效率优势，适用于地质样品中多种感兴趣元素的同时分离。
