Six assays for protein in urine were compared for linearity, ease of standardization, precision, comparability of assay values, technical ease of assay, and current cost. The assays investigated were three dye-binding techniques, a recent turbidimetric technique, the trichloroacetic acid--biuret reaction, and a tannic acid protein precipitation reaction with ferric chloride. All assays suffered...

IN THE TITLE COMPOUND [SYSTEMATIC NAME: N-(carbamoyl-carb-a-mo-thio-yl)benzamide], C(9)H(9)N(3)O(2)S, the benzoyl and terminal urea fragments adopt cisoid and transoid conformations, respectively, with respect to the S atom. The benzoyl and thio-biuret groups are almost coplanar, making a dihedral angle of 8.48 (5)°. The mol-ecular structure is stabilized by an intra-molecular N-H⋯O hydrogen bo...

A method is described for rapidly obtaining fresh extracts of microorganisms by percussion of the frozen cells. Filtrates giving the biuret reaction and yielding heavy precipitates upon the addition of acetic acid were obtained from the washed cells of cultures of yeast, hemolytic streptococcus, pneumococcus, B. coli, B. xerosis, B. dyphtheriae and the bacillus of bovine tuberculosis.

Interfering low molecular weight substances were removed from cerebro­ spinal fluid by gel filtration using Sephadex G-50-80 and total protein concen­ tration of the effluent was determined by the biuret reaction. Results of the proposed method were higher than comparable results obtained by a trichloro­ acetic acid turbidimetric method. Reproducibility of the method is acceptable.

Melamine (2,4,6-triamino-1,3,5-triazine) has been used on numerous occasions by individuals as a food adulterant to boost the apparent nitrogen content of food. Together with cyanuric acid, melamine causes acute kidney failure. In the recent infant formula incident, 150,000 children were hospitalized and several died. The WHO recently requested the development of a rapid method to quantitativel...

Biuret-modified tetraamidomacrocyclic cobalt complex [CoIII-bTAML]- is shown to catalyze electrochemical water oxidation at basic pH leading to the formation of O2. Electrochemical and spectroscopic studies indicate a high valent cobalt oxo intermediate isoelectronic to CoV(O) as the active oxidant. The kinetic isotope effect of 8.63 indicates an atom proton transfer mechanism.

A system is described which permits measurements,such as photometry, to be made on air-segmented streams, as in continuous-flow analysis. Elimination of -the “debubbler” step before measurement provides two basic assets: (1) more rapid attainment of steady-state conditions (lower interaction between samples), and (2) maintenance of the integrity of the bubbled analysis stream, permitting subseq...

Because of the importance of quantitative determination of protein in the research laboratory as well as in the food and feed industries (I), search for the ideal method continues unabated after many years. Methods available include nitrogen determination (Kjeldahl (2) and Dumas (3)), hydrolysis of the protein, derivatization of the amino acids with phthalaldehyde and fluorescence determination...