Pre-treatment Methods for Accurate Determination of Total Nitrogen and Organic Carbon Contents and their Stable Isotopic Compositions: Re-evaluation from Geological Reference Materials
Pre-treatment Methods for Accurate Determination of Total Nitrogen and Organic Carbon Contents and their Stable Isotopic Compositions: Re-evaluation from Geological Reference Materials
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准确测定总氮和有机碳含量及其稳定同位素组成的前处理方法：地质标准物质的再评价
DOI：
10.1111/ggr.12410
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发表时间：
2021
影响因子：
3.8
通讯作者：
Teruyuki Maruoka
中科院分区：
文献类型：
--
作者：
Wataru Fujisaki;Yohei Matsui;Hisahiro Ueda;Yusuke Sawaki;Katsuhiko Suzuki;Teruyuki Maruoka
本文报道了海洋、河流和湖泊地质标准物质(δ-1、δ-2、δ-1、SCO-2、JSD-3、JSD-4和JLK-1)的总氮(TN)、碳(TC)和有机碳(TOC)含量以及稳定同位素比值(JMS15NTN、JMS13CTC和JLK13Corg)。利用这个新获得的数据集，我们系统地研究了氮和碳测量的三种前处理方法的偏差：(1)不酸化(未经处理的方法)，(2)在不同条件下的盐酸酸化并随后用高纯水反复冲洗(漂洗法)和(3)在镀金银胶囊中的 酸化(胶囊法)。我们的结果表明，这种酸处理可以影响氮和碳的测量，除了古代地质RMS的碳数据。因此，氮的分析应该使用未经处理的样品，而碳的数据应该使用现代表层沉积物的胶囊法和古代沉积物的漂洗法(70 L-1HCl酸化)。我们认为，使用适当的前处理方法对于未来对古代/现代环境过程和机制得出新的解释至关重要。
This study reports total nitrogen (TN), carbon (TC) and organic carbon (TOC) contents, as well as stable isotopic ratios (δ15NTN, δ13CTCand δ13Corg), from marine, stream and lacustrine geological reference materials (JMs‐1, JMs‐2, SBC‐1, SCo‐2, JSd‐3, JSd‐4 and JLk‐1), which can be classified into two types; modern surface, and ancient, sediments. Using this newly obtained data set, we systematically investigated the biases of three pre‐treatment methods for nitrogen and carbon measurements: (1) non‐acidification (untreated method), (2) HCl acidification in various conditions and subsequent rinsing with high‐purity water repeatedly (rinse method) and (3)in situacidification in a gold‐coated silver capsule (capsule method). Our results showed that such acid pre‐treatments can affect both nitrogen and carbon measurements, except for the carbon data of the ancient geological RMs. Therefore, the nitrogen analysis should be conducted using untreated samples while carbon data should be obtained using the capsule method for modern surface sediments and the rinse method (6 mol l‐1HCl acidification at 70 °C) for ancient sediments. We believe that using appropriate pre‐treatment methods is crucial to deriving new interpretations of ancient/modern environmental processes and mechanisms in the future.