Interfacing an automatic elemental analyser with an isotope ratio mass sepectrometer: the potential for fully automated total nitrogen and nitrogen-15 analysis

Abstract

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.