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