GFZ German research centre for geo sciences

Laboratory for stable Isotopes (sediments and water)

We measure the stable isotopes of the light elements carbon (C), nitrogen (N), oxygen (O) and hydrogen (H) in continental geoarchives such as lake sediments and speleothems as well as in precipitation and surface water.

Stable isotopes are non-radioactive nuclides of an element with the same number of protons and different numbers of neutrons and thus different atomic masses. This results in different physical properties that can lead to a shift in the isotope ratios in a substance (in our case water, organic matter or carbonate). These isotope ratios leave fingerprints of past environmental conditions and can indicate changes in precipitation, temperatures, vegetation or organic productivity in our archives.

Shifts in isotope ratios during natural processes are often very small. These changes can be measured very accurately using isotope ratio mass spectrometers (IRMS) or cavity ring down spectroscopy (CRDS).

Reference: "Vom Monitoring zum Klimaarchiv" | https://doi.org/10.2312/GFZ.syserde.07.01.2

Instruments:

  • IRMS MAT253 (Thermo Fisher Scientific)
  • KIELIV carbonate device

Applications:

  • δ13C and δ18O in smallest samples (10 to 100 µg) with highest precision
  • δ13C, δ18O in CO2

Instruments:

  • IRMS DELTA V Advantage (Thermo Fisher Scientific)
  • Gasbench II

Applications:

  • δ13C and δ18O in bulk carbonates (100 to 250 µg)

Instruments:

  • IRMS DELTAplusXL (Thermo Fisher Scientific)
  • Elemental analyser EA Isolink

Applications:

  • δ13Corg, TOC, and δ15N, TN in sediments

Instruments:

  • Picarro L2120-i
  • Picarro L2130-i

Applications:

  • δ18O and dD in water samples

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