Noble Gas Lab - Technical Details
Established in the years 2004-2006, our lab is the most modern of only a handful of laboratories worldwide that can analyse all stable noble gases dissolved in water samples. It builds on the experience of two other leading laboratories, namely at the L-DEO, Columbia University, New York (Ludin et al., 1997) and at ETH Zurich (Beyerle et al., 2000).
Routine procedures for the analysis of major noble gas isotopes from ~ 20 ml water samples as well as ~ 1 cm3 gas samples are now established. Procedures for the analysis of much smaller (~ 1 µl) water samples from fluid inclusions are currently being developed.
Details on the system are described in a recent PhD-thesis (Friedrich, 2007) and will be published elsewhere soon.
GV 5400He Noble Gas Mass Spectrometer
Static vacuum mass spectrometer suitable for the measurement of He, Ne, Ar, Kr, Xe.
90° magnetic sector analyser, Nier type ion source, Faraday and Muliplier detectors.
High resolution (~ 600) and sensitivity (> 5x10-4 A/Torr for Ar), low background.
Installed in 2004
Fully automated, custom-built preparation line
Fully automated and computer controlled with ~ 30 pneumatic valves.
Cryogenic purification system operated between 8 and 300 K.
Ultra-high vacuum system (< 10-8 mbar).
Inlet systems for water, gas, and rock (fluid inclusion) samples.
Calibration and performance
Absolute calibration is performed against aliquots of an air standard.
Precision (reproducibility) for concentrations is < 1 % except for Xe (< 1.5 %).
Precision for major isotope ratios is usually < 0.5 % except for 3He/4He (< 2 %).
Standard water analyses take about 3 hours, blanks and calibrations are run overnight.
Ludin, A., Weppernig, R., Boenisch, G., and Schlosser, P., 1997. Mass spectrometric measurement of helium isotopes and tritium. Lamont-Doherty Earth Observatory, Technical Report.
Beyerle, U., Aeschbach-Hertig, W., Imboden, D. M., Baur, H., Graf, T., and Kipfer, R., 2000. A mass spectrometric system for the analysis of noble gases and tritium from water samples. Env. Sci. Technol. 34, 2042-2050.
Friedrich, R., 2007. Grundwassercharakterisierung mit Umwelttracern: Erkundung des Grundwassers der Odenwald-Region sowie Implementierung eines neuen Edelgas-Massenspektrometersystems. Dissertation, Universität Heidelberg, 271 pp.