Nitrogen isotopic fractionation in ammonia during adsorption on silicate surface.
Nitrogen isotopic fractionation in ammonia during adsorption on silicate surface.
复制标题
硅酸盐表面吸附过程中氨中的氮同位素分馏。
DOI：
10.1021/acsearthspacechem.6b00006
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发表时间：
2017
影响因子：
3.4
通讯作者：
N.
中科院分区：
文献类型：
--
作者：
Sugahara;H.;Takano;Y.;Ogawa;N.O.;Chikaraishi;Y. and Ohkouchi;N.
吸附是发生在各种界面的基本现象；然而，对于大多数分子来说，与此过程相关的稳定同位素中的同位素分馏尚未得到充分记录。在本研究中，我们对蒙脱石和皂石这两种硅酸盐矿物进行了氨吸附实验，以确定过程中的氮同位素分馏。相对于初始氨，吸附在这些矿物质上的氨在 15N 中富集高达+44‰。 15N富集程度与氨吸附率呈负相关。与其他物理化学（例如蒸发）或生物（例如酶反应）过程中报道的富集相比，这些富集非常大。基于这些结果，我们可以预测15NH3通过矿物表面吸附而优先富集，这可以解释太阳系中15N/14N比的不均匀性。
Adsorption is a fundamental phenomenon that occurs at various interfaces; however, the isotopic fractionation in stable isotopes associated with this process has not yet been well documented for most molecules. In this study, we conducted ammonia adsorption experiments on two silicate minerals, montmorillonite and saponite, to determine the nitrogen isotopic fractionation during the process. Ammonia adsorbed on these minerals is up to +44‰ enriched in15N relative to initial ammonia. The degree of15N enrichment has a negative correlation with the adsorption ratio of ammonia. These enrichments are remarkably large compared to those reported in other physicochemical (e.g., evaporation) or biological (e.g., enzymatic reaction) processes. On the basis of these results, we can predict that preferential accumulation of15NH3occurs by adsorption on mineral surfaces, which may explain the heterogeneity of the15N/14N ratio in the solar system.