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

Detailed here is a method for extracting and analyzing oxygen and hydrogen isotopes from 10 L-sized water samples. Based on the traditional C02-H20 equilibration technique, the oxygen isotope exchange reaction is done exclusively in sealed 6-mm (o.d.) Pyrex tubes at 25 C, with full isotope exchange completed in at least 28 h. Using the same water sample employed in the 180 equilibration, D/H extractions are done in separate sealed 6-nim (o.d.) Pyrex tubes by reaction with Zn at 450C 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.

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