A microscale method for colorimetric determination of urea in soil extracts

A new simple semimicro method for colorimetric determination of urea.

A sensitive method for the colorimetric determination of urea.

A method is described for the direct colorimetric determination of urea in biological fluids. The method depends on the reaction (first described by Wheatley, 1948) between urea, diacetylmonoxime, and phenylanthranilic acid in the presence of controlled amounts of oxidant; chloride ions are included to sensitize the reaction; manganous ions stabilize the resultant colour; and phosphate enables ...

A Direct Colorimetric Method for the Determination of Urea in Blood and Urine

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...

The Direct Colorimetric Determination of Urea in Blood and Urine

Methods for the determination of urea in biological fluids have passed through an interesting cycle (cf. Peters and Van Slyke (3) pp. 539-544). The earliest procedures were strictly chemical ones, involving precipitation of the urea as an insoluble mercury complex or decomposition of the urea by means of heat or hypobromite. The use of the highly specific enzyme urease occurring in the jack and...