SREL Reprint #2381

On-line technique for measuring stable oxygen and hydrogen isotopes from microliter quantities of water

Richard A. Socki1, Christopher S. Romanek2, and Everett K. Gibson, Jr.3

1C-23 Lockheed Martin, 2400 NASA Road, Houston, Texas 77058
2Savannah River Ecology Lab, University of Georgia, Drawer E, Aiken, South Carolina 29802
3SN4, NASA Johnson Space Center, Houston, Texas 77058

Abstract: Detailed here is a method for extracting and analyzing oxygen and hydrogen isotopes from 10 µL-sized water samples. Based on the traditional CO2–H20 equilibration technique, the oxygen isotope exchange reaction is done exclusively in sealed 6-mm (o.d.) Pyrex tubes at 25ºC, 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 450ºC 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.

SREL Reprint #2381

Socki, R.A., C.S. Romanek, and E.K. Gibson, Jr. 1999. On-line technique for measuring stable oxygen and hydrogen isotopes from microliter quantities of water. Analytical Chemistry 71:2250-2253.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).