The estimation of ammonia using the indophenol blue reaction.

University Department of Clinical Biochemistry, Royal Victoria Infirmary, Newcastle upon TyneGreat Britain
Clinica Chimica Acta (Impact Factor: 2.85). 09/1966; 14(2):185-94. DOI: 10.1016/0009-8981(66)90085-4
Source: PubMed

ABSTRACT The addition of sodium hypochlorite solution of pH 12.5 to an ammonia solution before the addition of sodium phenate has been shown to increase the sensitivity and accuracy of the indophenol blue reaction. This reaction is not temperature-dependent over the range −5° to +25°. The pH of the phenate solution is much less critical when it is added after the hypochlorite; a reagent with a pH in the range 10.6–11.2 is quite suitable.This modified method may be applied to the later stages of Fenton's1 method of estimating plasma ammonia and while it increases the sensitivity and accuracy it does not impair the specificity.

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