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Article
July 12, 1913

CLINICAL METHODS FOR ESTIMATION OF TOTAL NITROGEN AND AMMONIANITROGEN IN URINE

Author Affiliations

PITTSBURGH, PA.

From the Biochemical Laboratory of the Western Pennsylvania Hospital, Pittsburgh, Pa.

JAMA. 1913;61(2):87-88. doi:10.1001/jama.1913.04350020013006
Abstract

The value of the determination of the so-called "ammonia coefficient" is well known to all workers in clinical medicine. One of the drawbacks to the more universal use of this determination has been the necessity of a fairly well-equipped laboratory for its performance.

The following simplified titration methods for the estimation of the total nitrogen and ammonia-nitrogen of urine depends on the fact that when a neutral solution of an ammonium salt is treated with formaldehyd, combination occurs with the formation of hexamethylenetetramin and the liberation of a corresponding amount of acid which can be titrated with tenth-normal sodium hydroxid. The reaction is as follows:

4NH4Cl +6H.CHO+4NaOH=(CH2)6N4+10H2O+4NaCl.

I have found that the methods to be described are sufficiently accurate for clinical needs and may be carried out in the most modest laboratory.

METHOD FOR THE ESTIMATION OF TOTAL NITROGEN OF URINE1 

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