An interface between an automatic nitrogen analyser and an isotope mass spectrometer is described. The interface enables total nitrogen analyses and nitrogen isotope ratio measurements to be made semi-automatically, at the rate of 12 h-1. The precision of the measurements was at the detection limit of the mass spectrometer (0.00026 atom-% 15N; ±0.7‰). No significant cross-contamination between samples was observed (<0.02% carry over). The potential for full automation and extension of the interface for other stable isotope measurements is discussed.
- Automatic nitrogen analysis
- Elemental gas chromatograph - mass spectrometer interface
- Nitrogen-15 isotope mass spectrometry