Accession Number : AD0006106


Title :   The Determination of Nitrogen by the Dumas Method


Corporate Author : JOHNS HOPKINS UNIV BALTIMORE MD


Personal Author(s) : Corwin, Alsoph H ; Claggett, Ann L


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/006106.pdf


Report Date : 30 Jun 1952


Pagination or Media Count : 27


Abstract : Dumas analyses of the difficultly combustible compounds, uric acid (I) and benzaldehyde-2, 4-dinitrophenylhydrazone (II), gave average values for N of 32.28% for I (33.33% calculated) and 18.83% for II (19.57% calculated). The apparatus included: a Fisher combustion furnace with constant current heating; an H-O generator with an automatic gas relief assembly; a nitrometer; and an Hg acid injector. The sublimate had a Cu:N ratio suggestive of a cuprous complex of cyanogen; a Cu-cracking surface which was produced in the combustion with H prevented the formation of the sublimate. CO will yield high results if the internal temperature gradient of the furnace is held as small as possible. Si was partially satisfactory in the tube; V, Zr, and Ti were unsatisfactory. 2,4-Dicarbethoxy-3-methyl-5-bromopyrrole was employed as a standard in N determinations when Br was present. An increase in H improved the results; H generation at the rate of 0.5 amp was considered acceptable with a bromopyrrole analysis of 4.59%. No difficulty was encountered in the presence of Cl, I, or S.


Descriptors :   *CHEMICAL INDICATORS , *COMBUSTION PRODUCTS , TEMPERATURE GRADIENTS , INTERNAL , HEATING , COPPER COMPOUNDS , INJECTORS , AUTOMATIC , FURNACES , ACIDS , CYANOGEN , GASES , RATIOS , YIELD


Subject Categories : Industrial Chemistry and Chemical Processing


Distribution Statement : APPROVED FOR PUBLIC RELEASE