Determination of Ultra Low Content of Nitrogen in Metal and Slag by Ion-Chromatography

Effects of HCl, Fe, Na and K in the determination of nitrogen as NH4+ have been studied by the method of Ion-chromatography. The analyzed value of nitrogen was reduced in the presence of HCl (>9×10−5 mol) and K (≥2 μg) in the injected solution, while that was scarcely influenced by 120 μg of Fe or 30 μg of Na. In the analysis of ultra low content of nitrogen in steel or slag, 1 mass ppm of nitrogen in the sample was determined with CV-value=3.5% by a combination of the steam-distillation method and ion-chromatography.