Automated blood glucose and urea nitrogen procedures have been modified for use with the Technicon 15-mm. tubular flow-cell colorimeter to take advantage of the resulting increased sensitivity and economy. Flow diagrams for these procedures as well as for the simultaneous determination of glucose and urea are presented. Recovery and reproducibility data are given to indicate the reliability of ...

An enzymatic, fluorometric method is described for determination of serum urea on silicone-rubber pads. In this method, the reagents are lyophilized on the surface of the pads, NADH on one side and a mixture of urease, glutamate dehydrogenase, and alpha-ketoglutarate on the other. The rate of disappearance of NADH fluorescence at 460nm (excitation wavelength, 340 nm) is monitored and related to...

A quantitative method for the determination of urea in serum was studied. An ion chromatograph (IC) with a conductivity detector was used in this method, where the chromatograph was modified by placing an immobilized urease column between the injection loop and a guard column of the cation analysis column. Immobilized urease was prepared by the adsorption of urease on cedar sawdust with triethy...

A simplified method for the determination of the rate of synthesis of albumin after the i. v. injection of C-carbonate is described. A number of experiments to check the accuracy of the CO2 measurements is reported. Good agreement is obtained between the specific activity of urinary urea, measured by means of our method and by the manometric method. Recoveries of 101.9 and 101.1% respectively a...

An electrical transducer for urea is described. The excellent stability of various types of urease enzyme electrodes developed in the author's laboratory is due to understanding the parameters which affect immobilized enzyme stability. Preliminary experiments have shown that a liquid layer of urease trapped in a double cellophane layer over a cation electrode may produce a useful enzyme electro...

distribution of urea in the ocean and the An automated method for the determination use of 15N-labeled urea enrichment techof urea in seawater, adapted to a Technicon AutoAnalyzer, is sensitive enough to detect niques require a method that is rapid, urea at the 0.05 pg-atom urea-N liter-l level. sensitive, and convenient for use at sea. An adaptation of the diacetyl monoxime The importance of u...

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...