An improved method for the simple and accurate colorimetric determination of urea with Ehrlich's reagent

Abstract

An improved method for the colorimetric determination of urea is described. The method is simple, requiring a deproteinized filtrate obtained after treatment of a small quantity of whole oxalated blood, serum, plasma or urine with 12.5% trichloracetic acid containing 50 g. activated carbon. The addition of Ehrlich's reagent to this filtrate results in the immediate production of a stable yellow colour. The determination is accurate, very sensitive and rapid, taking place in only 10 minutes.