ABSTRACT
The 1990s have witnessed a dramatic increase in research on instrumentation and methods in high-precision isotope ratio mass spectrometry for determination of isotopes of organic elements. The dual-inlet (DI) approach remains the technique of choice for highest precision analyses. However, the sample must be admitted to the instrument as a specific gas, CO2, H2, N2, or SO2, requiring conversion to one of these gases while maintaining isotopic representation of the original sample. Continuous flow techniques have been applied to improve the sensitivity and speed of non-compound-specific isotope analysis other than elemental analyzers. Traditionally, static DI analysis is used to determine the hydrogen isotope ratio of pure hydrogen gas derived from water and organic compounds. The conversion of the analyte to isotopically representative hydrogen gas can be undertaken in one of many ways.
