Apparatus for determining small amounts of nitrogen

• US 4,081,345 A
• Filed: 07/30/1976
• Issued: 03/28/1978
• Est. Priority Date: 08/04/1975
• Status: Expired due to Term

• Current Assignee: Max-Planck-Gesellschaft Zur Foerderung Der Wissenschaften e.V. (Max-Planck-Gesellschaft zur Frderung der Wissenschaften e)
• Original Assignee: Max-Planck-Gesellschaft Zur Foerderung Der Wissenschaften e.V. (Max-Planck-Gesellschaft zur Frderung der Wissenschaften e)
• Inventors: Tolg, Gunter, Werner, Wido
• Primary Examiner(s): Tung, T.
• Application Number:
  US05/710,233
• Time in Patent Office: 606 Days
• Field of Search: 204/1 N, 204/195 R, 204/195 T, 23/230 R, 23/232 E, 23/253 R, 23/254 E, 23/255 E, 23/230 M
• US Class Current: 204/405
• CPC Class Codes: G01N 27/44 using electrolysis to generate a reagent, e.g. for titration
• CPC Class Codes: G01N 31/002 Determining nitrogen by transformation into ammonia, e.g. KJELDAHL method
• CPC Class Codes: Y10T 436/176152 Total nitrogen determined

Abstract

The nitrogen content of a substance is determined by digesting the substa in a sealed container at superatmospheric pressure in a liquid acid medium until the nitrogen is converted to ammonium ions, the medium is alkalinized, and the ammonia liberated thereby is driven from the alkalinized medium into an acidic aqueous medium by steam distillation in a closed system in which the steam used is generated from the acidic aqueous medium. The latter then is adjusted to a weakly alkaline pH, and the ammonia present is oxidized to nitrogen by hypobromite ions electrolytically generated from bromide ions in the adjusted solution. The amount of current consumed is determined as a measure of the nitrogen originally present.

Claims

1. Apparatus for analyzing a substance for nitrogen content comprising:

(a) a vessel adapted to hold a medium prepared by digesting said substance in a liquid medium until the nitrogen content thereof is converted to ammonium ions and alkalinizing said medium;

(b) first heating means for heating the contents of said vessel to a temperature above the boiling point of water and for thereby generating vapors from said contents;

(c) a receiver adapted to hold an acidic aqueous medium;

(d) second heating means for heating the contents of said receiver to a temperature higher than the boiling point of said acidic aqueous medium and for thereby generating steam;

(e) first connecting tubing connecting said vessel to said receiver for introducing the material of said vapors into the acidic medium in said receiver;

(f) second connecting tubing connecting said receiver to said vessel for introducing steam generated in said receiver into said contents of said vessel;

(g) condenser means interposed between said first connecting tubing and said receiver for condensing said material of said vapors; and

(h) a plurality of electrodes projecting into said receiver, said vessel, said receiver, said first tubing, said second tubing and said condenser means constituting a closed system sealed from the ambient atmosphere.

2. Apparatus as set forth in claim 1, wherein said plurality of electrodes includes four electrodes insulated from each other.