Stable Isotope Labs

The RWI Stable Isotope Labs are equipped for the analyses of stable water isotopes (δ18O, δ2H) in groundwater and experiment solutions and stable isotopes of carbon (δ13C) and oxygen (δ18O) in solid phases (minerals, bulk rock).

Isotopes of water

Stable water isotopes (δ18O, δ2H) in groundwater and experiment solutions are analysed using Cavity Ring Down Spectrometry CRDS [Picarro L2120-i]. Standardisation ranges cover the normal δ18O, δ2H range observed in snow, ice and groundwater from cold and warm climate regions. In addition different Lab-internal standardisation ranges exist for high-D contents for the analyses of experiment solutions traced with deuterium (D).

The quality of δ18O, δ2H analyses is ensured by regular measurements of IAEA approved control standards regular participation in comparative tests with other isotope laboratories.

Isotopes of carbonates

Stable carbon (δ13C) and oxygen (δ18O) isotope analysis on carbonate solid phases are conducted by phosphoric acid digestion and conventional isotope ratio mass spectrometric techniques (IRMS).

The lab’s instrumentation consists of:

  • Delta V Advantage coupled to a Thermo Gasbench II
  • Precision dentist drills and a motorized triaxial drill-stage for localised extraction of sample material from larger blocks
  • New Wave Research MicroMill system for precision milling and extraction of sample material from small slabs or thicksections
  • Mettler AT20 precision laboratory scale (2 µg resolution) in a sealed weighing room.