Présentations Colloques

Oral Presentation
Session 8.04: Isotopic and residence time tracers
Labasque Thierry
Membrane inlet mass spectrometer for hydrogeological studies
Dissolved gases are useful tools in hydrogeology. They inform us on physical and biogeochemical processes along the flow paths of groundwater (noble gases temperature, excess air, redox processes, groundwater ages,...). The sampling and measurement of dissolved gases are often complex and require sometimes long and costly analytical methods. Recently, field membrane inlet mass spectrometer (MIMS) technologies have been developed and optimized to environmental studies. We present here our continuous flow MIMS (CF-MIMS) for field measurements of dissolved gases- H2, He, Ne, Ar, N2, Kr, Xe, CH4, N2O, O2 and CO2. Calibration, optimization and limitations of the measurements are presented. The results of a gas tracer experiment and a real time dissolved gases profile in borehole are presented. This new high frequency field measurement technique offers new information for hydrogeological studies.