Analysis of Compounds containing Heavy Nitrogen (15N) by Infrared Absorption Spectra

A new analytical procedure using infrared absorption spectra was established for determination of compounds containing heavy nitrogen (15N). This procedure is a combination of the Kjeldahl method and gas determination by infrared spectrum. Compounds containing heavy nitrogen is converted to ammonia, and qualitative and quantitative analyses are carried out after determination of key bands of 15NH3 from the difference between 14NH3 and 15NH3 in the symmetric deformation vibration of NH3 in the region of 800∼1200 cm-1. Precision of the present procedure is somewhat lower than that by mass spectrometer but the procedure is far more simple and will be effective for various experiments using heavy nitrogen (15N).