Automatic nitrogen-15 analyser for use in biological research

Abstract

An automatic nitrogen-15 analyser capable of analysing 12–20 samples per hour has been developed. The generation of pure nitrogen gas from the sample is carried out automatically, the nitrogen isotope ratio is determined by emission spectrometry and the results are calculated as atom-% nitrogen-15. The total nitrogen content of the sample is also determined. Sample masses can vary between 0.5 and 100 mg and only 2–10 µg amounts of N are necessary for accurate determinations.