Effects of cryogenic vacuum distillation on the stable isotope ratios of soil water

• Tsuruta Kenji

  Department of Forest Soils, Forestry and Forest Products Research Institute, Japan

• Yamamoto Hiroyuki

  Graduate School of Agriculture, Kyoto University, Japan

• Katsuyama Masanori

  Graduate School of Agriculture, Kyoto University, Japan

• Kosugi Yoshiko

  Graduate School of Agriculture, Kyoto University, Japan

• Okumura Motonori

  Research Institute of Environment, Agriculture, and Fisheries, Osaka Prefecture, Japan

• Matsuo Naoko

  Graduate School of Bioresources, Mie University, Japan

Abstract

Cryogenic vacuum distillation (CVD) methods have been widely used to extract water from unsaturated soil materials. However, recent studies have reported that extraction conditions (e.g. extraction time) and soil type can influence the stable isotope ratios of soil water extracted by CVD. We examined (i) the effects of extraction time on the stable isotope ratios of soil water extracted by CVD, and (ii) how the stable isotope ratios differed from those of soil water extracted by other methods. We first examined extraction times of 1–6 h, and observed no significant differences in the δ²H or δ¹⁸O values of extracted soil water for extraction times >2 h. However, extraction for 1 h collected only 48% of soil water, and the δ²H and δ¹⁸O values were significantly lower than those for extraction times >2 h. We then compared the stable isotope ratios of soil water extracted by CVD and centrifugation. Although the stable isotope ratios for both extraction methods were within the range of that of rainwater, the stable isotope ratios for water extracted by CVD were lower than those for water extracted by centrifugation. Our results highlight questions surrounding the use of CVD for stable isotope analysis of soil water.

Journal

• Hydrological Research Letters

  Hydrological Research Letters 13 (1), 1-6, 2019

  Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

Keywords

• Earth and Planetary Sciences (miscellaneous)
• Water Science and Technology

Details

• CRID: 1390564238072680576
• NII Article ID: 130007586372
• DOI: 10.3178/hrl.13.1
• ISSN: 18823416
• Web Site: https://www.jstage.jst.go.jp/article/hrl/13/1/13_1/_pdf
• Text Lang: ja
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed