Diersing Carlynn, Li Yue, Wang Lixin
Department of Earth and Environmental Sciences, Indiana University Indianapolis, Indianapolis, Indiana, USA.
Rapid Commun Mass Spectrom. 2025 Apr 30;39(8):e9988. doi: 10.1002/rcm.9988.
Fog, dew, and rain are crucial for sustaining ecosystem functions, especially in water-limited regions. However, they are subject to isotopic changes during storage due to their usual small sample volumes and inherent sensitivity to atmospheric particulates. Understanding long-term storage effects on these water samples is essential for ensuring isotopic integrity.
In this study, the extent of such changes in the isotopic compositions (δH, δO, and δO) of fog, dew, and rain was investigated under different storage times (4.5-9 years) and different bottle fill levels (4.8%-92.4%) using the Los Gatos Research Inc. GLA431 series analyzer.
The long-term storage could lead to a large variation in oxygen isotopes of fog with minor effects on dew and rain samples. The isotopic changes of δO for fog waters were negatively correlated with the bottle fill level (p < 0.01) but positively related to storage time (p < 0.01). Chemical reactions between solutes and water molecules within fog samples may induce oxygen fractionation, leading to the high sensitivity of fog oxygen isotopes to long-term storage. No significant changes in δH values were observed for the three water types.
Our findings could help understand the long-term isotopic accuracy and precision of fog, dew, and rainwaters by providing information on isotopic changes after long-term storage.
雾、露水和雨水对于维持生态系统功能至关重要，尤其是在水资源有限的地区。然而，由于它们通常样本量小且对大气颗粒物具有固有敏感性，在储存过程中会发生同位素变化。了解这些水样的长期储存影响对于确保同位素完整性至关重要。
在本研究中，使用洛斯加托斯研究公司的GLA431系列分析仪，研究了雾、露水和雨水的同位素组成（δH、δO和δO）在不同储存时间（4.5 - 9年）和不同瓶子填充水平（4.8% - 92.4%）下的变化程度。
长期储存可能导致雾的氧同位素发生较大变化，而对露水和雨水样本影响较小。雾水的δO同位素变化与瓶子填充水平呈负相关（p < 0.01），但与储存时间呈正相关（p < 0.01）。雾样本中溶质与水分子之间的化学反应可能会引发氧分馏，导致雾氧同位素对长期储存具有高敏感性。对于这三种水样，未观察到δH值有显著变化。
我们的研究结果通过提供长期储存后同位素变化的信息，有助于了解雾、露水和雨水的长期同位素准确性和精度。
