Ammonium Sulfamate as Substitute for Lead Peroxide in Microdetermination of Carbon and Hydrogen

Abstract

The oxides of nitrogen formed in the combustion anal) -sis of nitrogen-containing compounds can be removed effectively by ammonium sulfamate dispersed on silica gel. This reagent, placed between the water absorption tube and the carbon dioxide absorption tube, removes oxides of nitrogen by reducing them to nitrogen and nitrous oxide. The use of this reagent eliminates the need for the lead peroxide section usually placed in the exit end of the combustion tube. The analytical values obtained when ammonium sulfamate is used are not notably more precise or more accurate than when a lead peroxide filling is used. However, the use of a substitute for lead peroxide eliminates the highly erratic values observed periodically when any of the equilibria involving the lead peroxide surface become upset b? exposure of the f i l h g to an excess of nitrogen oxides.