gas chromatograph - pyrolyses - isotope ratio mass spectrometer (GC-Py-IRMS)

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The applied instrument is an isotope ratio mass spectrometer being coupled via an “online” pyrolysis reactor to a gas chromatograph. Such a coupling is used for compound-specific hydrogen and oxygen isotope analyses. The latter became an invaluable tool amongst others in paleoclimate and -environmental research during the last two decades. Particularly, the hydrogen isotope analyses of leaf wax-derived n-alkane biomarkers is meanwhile well established in many laboratories worldwide. By contrast, compound-specific oxygen isotope analyses - e.g. of plant-derived sugar biomarkers - were hitherto realized in only three research laboratories worldwide.The aim of our application is to continue the development and application of compound-specific oxygen isotope analyses. Within one research project we will develop and test a new type of oxygen pyrolysis reactor. Within other research projects, we aim at contributing to the reconstruction of late Quaternary and Holocene climate, environmental and human history of various study areas (South Africa, Bale Mountains in Ethiopia, Mongolia, high arctic islands and the Alps). Lake sediments, peats and organic material of ground ice and permafrost serve as archives. Particularly, the applicant and his team will focus on the coupling of compound-specific hydrogen and oxygen isotope results. By using the reconstructed leaf water or lake water, this coupling allows (i) to reconstruct relative air humidity (--> paleohygrometrie) and (ii) to reconstruct the isotopic composition of precipitation more robust than based on compound-specific hydrogen or oxygen isotope results alone.