title: On-line technique for measuring stable oxygen and hydrogen isotopes from microliter quantities of water.
abstract: Detailed here is a method for extracting and analyzing oxygen and hydrogen isotopes from 10 microL-sized water samples. Based on the traditional CO2-H2O equilibration technique, the oxygen isotope exchange reaction is done exclusively in sealed 6-mm (o.d.) Pyrex tubes at 25 degrees C, with full isotope exchange completed in at least 28 h. Using the same water sample employed in the 18O equilibration, D/H extractions are done in separate sealed 6-mm (o.d.) Pyrex tubes by reaction with Zn at 450 degrees C to form H2(g). Provided that a correction factor is applied to 18O analyses, accuracy and precision for both 18O and D/H are comparable to standard techniques using much larger samples.
authors.affiliation: Lockheed Martin, Houston, Texas 77058, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Socki
authors.forename: C S
authors.initials: CS
authors.lastname: Romanek
authors.forename: E K
authors.initials: EK
authors.lastname: Gibson
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000295:instrumentation* / Q000379:methods*; D006859:Hydrogen / Q000032:analysis*; D013058:Mass Spectrometry / Q000379:methods; D010103:Oxygen Isotopes / Q000032:analysis*; D012680:Sensitivity and Specificity; D014867:Water / Q000032:analysis*
chemical_list: D010103:Oxygen Isotopes; D014867:Water; D006859:Hydrogen