Abstract:
The stable isotopes of hydrogen and oxygen (
δ2H and
δ18O) are excellent tracers for studying on the natural water cycle. New analytical techniques for stable isotope ratio measurements have been rapidly developed over the past decade. These techniques include mass spectrometry with online or continuous flow apparatus for sample introduction, and laser spectroscopy. In this paper, the
δ18O value of water samples was determined by CO
2-H
2O equilibration-isotope ratio mass spectrometry and laser spectroscopy, and the
δ2H value was determined by the laser spectroscopy and high-temperature conversion/elemental analysis-isotope ratio mass spectrometry (HTC-IRMS). The results show that the measurement accuracy and precision of two methods are almost same when determining the
δ2H and
δ18O value of the groundwater, seawater and meteoric water samples. While, laser spectroscopy has the advantage of fast and efficient, low cost and few sample consumption. The two methods were also used to determine the extraction water from soil samples. The
δ18O value deviation between the measurement and true value of laser spectroscopy technology is 0.34‰, and that of mass spectrometry is less than 0.10‰. The
δ2H value deviation between the measurement and true value of laser spectroscopy technology is 2.3‰, and that of mass spectrometry is less than 0.6‰. The results indicate that mass spectrometry is much better than laser spectroscopy technology for the determination of water samples containing organic matter.