title: An instrumental method for nitrogen-15 and total nitrogen by combined system of mass spectrometer and automatic nitrogen analyzer.
mesh_terms: D000645:Ammonium Sulfate; D001322:Autoanalysis; D013058:Mass Spectrometry; D008722:Methods; D009584:Nitrogen / Q000032:analysis*; D009587:Nitrogen Isotopes; D010944:Plants / Q000032:analysis; D013045:Species Specificity; D013213:Starch
chemical_list: D009587:Nitrogen Isotopes; D013213:Starch; D009584:Nitrogen; D000645:Ammonium Sulfate