New on-line methods for determining the deuterium/hydrogen composition of water and hydrocarbon gases using O(2-) ion-conducting solid electrolyte reactor.
BACKGROUND
The deuterium/hydrogen (D/H) composition of water and hydrocarbon gases is widely used in geological, environmental and petroleum studies. The aim of this work was to develop a simple reduction zirconium dioxide solid electrolyte reactor (SER) for water decomposition and new methods for measuring hydrogen isotope ratios in water and hydrocarbon gases.


METHODS
δ(2)H(VSMOW) values were determined using two new different on-line methods: solid electrolyte reactor isotope ratio mass spectrometry (SER-IRMS) for water and gas chromatography combustion solid electrolyte reactor isotope ratio mass spectrometry (GC-C-SER-IRMS) for hydrocarbon gases.


RESULTS
We have designed a solid electrolyte reactor based on oxygen ion-conducting zirconium dioxide stabilized by yttria (Y(2)O(3)). The reactor was used for catalytic electrochemical decomposition of water in a helium carrier gas. The solid electrolyte reactor has a small internal volume of 0.1 cm(3). It was operated at a temperature of ~950 °C. The total time of analysis for determining the hydrogen isotope ratio in water was 150 s. A typical water sample volume was about 0.2 μL (split ratio 500:1). The precision of the δ(2) H(VSMOW) measurements for water was better than or equal to 2.2‰ and that for hydrocarbon gases was within 0.5-3.0‰.


CONCLUSIONS
Fast, simple and accurate on-line methods (SER-IRMS and GC-C-SER-IRMS) were developed. The SER-IRMS method makes it possible to work with small water samples. Although the GC-C-SER-IRMS method was developed for hydrocarbons, it can also be used for other organic gases and their mixtures. The new solid electrolyte reactor for water decomposition is low cost and the ceramic tube is inexpensive.
Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Kosygin St. 19, Moscow 119991, Russia. vsev@geokhi.ru
Vyacheslav S
VS
Sevastyanov
Nikolai
N
Pedentchouk
Nataliya E
NE
Babulevich
Eric M
EM
Galimov
D000838:Anions / Q000737:chemistry; D003903:Deuterium / Q000032:analysis*; D004573:Electrolytes / Q000737:chemistry; D006859:Hydrogen / Q000032:analysis*; D013058:Mass Spectrometry / Q000295:instrumentation* / Q000379:methods*; D008697:Methane / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D015203:Reproducibility of Results; D013696:Temperature; D014867:Water / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry
D000838:Anions; D004573:Electrolytes; D014867:Water; D006859:Hydrogen; D003903:Deuterium; D015040:Zirconium; D008697:Methane; C028541:zirconium oxide; D010100:Oxygen