title: First real-time measurement of the evolving 2H/1H ratio during water evaporation from plant leaves.
abstract: We have studied the temporal behaviour of the deuterium isotope ratio of water vapour emerging from a freshly cut plant leaf placed in a dry nitrogen atmosphere. The leaf material was placed directly inside the sample gas cell of the stable isotope ratio infrared spectrometer. At the reduced pressure ( approximately 40 mbar) inside the cell, the appearance of water evaporating from the leaf is easily probed by the spectrometer, as well as the evolving isotope ratios, with a precision of about 1 per thousand. The demonstration experiment we describe measures the 2H/1H isotope ratio only, but the experiment can be easily extended to include the 18O/16O and 17O/16O isotope ratios. Plant leaf water isotope ratios provide important information towards quantification of the different components in the ecosystem water and carbon dioxide exchange.
authors.affiliation: CIO-Center for Isotope Research, University of Groningen, Nijenborgh, 4, 9747, AG Groningen, The Netherlands. e.r.t.kerstel@rug.nl
authors.forename: Erik R T
authors.initials: ER
authors.lastname: Kerstel
authors.forename: L Gerko van der
authors.initials: LG
authors.lastname: Wel
authors.forename: Harro A J
authors.initials: HA
authors.lastname: Meijer
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry; D003903:Deuterium / Q000032:analysis*; D017753:Ecosystem; D006859:Hydrogen / Q000032:analysis*; D007554:Isotopes / Q000032:analysis*; D010103:Oxygen Isotopes / Q000032:analysis; D018515:Plant Leaves / Q000502:physiology*; D013055:Spectrophotometry, Infrared / Q000379:methods; D013997:Time Factors; D014867:Water / Q000737:chemistry*
chemical_list: D007554:Isotopes; D010103:Oxygen Isotopes; D014867:Water; D002245:Carbon Dioxide; D006859:Hydrogen; D003903:Deuterium