Introduction to SIRMS

SIRMS provides analysis of isotopic ratios of the light stable isotopes C, N, O, S and H. 

Sample introduction methods 

Samples are introduced to the ion source as pure gas (dual inlet - DI) or carried on a flow of helium carrier gas (continuous flow - CF). A range of preparation systems are available to convert solid, liquid and gas samples containing stable isotopes into a gas that can be analyzed, while preserving the isotopic signature of the original sample. The light elements, their stable isotopes and the gases used for analysis are listed in the table below:

SIRMS Introduction table

Analyser principle of operation (Perspective) 

The ion source is a Nier type electron impact source, with 8 kV and 5 kV acceleration potentials used for the Perspective and Horizon IRMS respectively. Ions are separated by m/z in a magnetic sector. Quadratic zoom" lenses allow ion beams to be electrostatically deflected and focused into Faraday detectors. Up to 6 ion beams can be simultaneously collected and analyzed. 

Perspective Schematic