Thermo Finnigan Deltaplus XP isotope ratio mass spectrometer (IRMS)
The laboratory has a Thermo Finnigan Deltaplus XP isotope ratio mass spectrometer (IRMS), which is specially designed for measurement of light environmental stable isotopes 2H, 13C, 15N, 18O, 34S is a sensitive and selective instrument with application in hydrology, geology, environmental protection, paleoclimate.
Prior to stable isotope ratio measurements different samples has to be brought in gaseous form. A host of preparation methods have been developed and improved to convert different sample compounds to an appropriate gas including H2, CO, CO2, N2, and SO2. The measured values expressed in delta notation like δ2H, δ13C, δ15N, δ18O, δ34S The delta values are defined as follows: δ (‰) = (Rsample/ Rreference-1) * 1000, where R is the 13C/12C, 15N/14N or 34S/32S etc. ratio in the sample or in the international reference. The isotope results were calculated on the basis of the known values of international standard materials.
The Elemental Analyser (Fisons NA1500 NCS) is based on the complete and instantaneous oxidation of the sample by flash combustion which converts all organic and inorganic substances into combustion products. The resulting combustion gases pass through a reduction furnace and are swept into the chromatographic column by the carrier gas (helium). The gases are separated in the column and detected by the IRMS (δ13C, δ15N, δ34S). Isotopic analyses of water samples or carbonates are carried out with an automated GASBENCH II sample preparation device attached to the IRMS. Hydrogen and oxygen isotopes of the water, carbon and oxygen isotopes of carbonate samples are measured by this method. The high temperature conversion elemental analyser (TC/EA) coupled to the IRMS is suitable to determine the δ2H and δ18O values of solid samples and of fluid samples as well.