Compound specific analyses of 13C and D/H on gasses and n-alkanes
δ13C or δD of n-alkanes are measured on a Thermo Scientific GC-isolink with a Gerstel CIS injector and a Delta V plus isotope ratio mass spectrometer. Sample preparation depends on the starting material and purpose of analysis. Currently we are developing the preparation protocols for extracting leaf waxes from lake sediments.
Typically, 1 μl samples are injected with an injector and GC temperature of 40°C. The injector as ramped to 320°C while the CG is kept at 40°C for 1 min. The GC is then ramped to 320 °C with a total runtime of 1h 15min. The n-alkanes are separated on a GC column and passed to a conditioned alumina pyrolysis (1420°C) or combustion (1030°C) furnace for δD or δ13C analyses respectively.