Accession Number:

AD0006106

Title:

The Determination of Nitrogen by the Dumas Method

Descriptive Note:

Corporate Author:

JOHNS HOPKINS UNIV BALTIMORE MD

Personal Author(s):

Report Date:

1952-06-30

Pagination or Media Count:

27.0

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 CuN 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.

Subject Categories:

  • Industrial Chemistry and Chemical Processing

Distribution Statement:

APPROVED FOR PUBLIC RELEASE