scholarly journals Colorimetric determination of urea using diacetyl monoxime with strong acids

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259760
Author(s):  
Noah James Langenfeld ◽  
Lauren Elizabeth Payne ◽  
Bruce Bugbee
Keyword(s):  
Measurement Techniques ◽  
Color Stability ◽  
Colorimetric Determination ◽  
Diacetyl Monoxime ◽  
Simple Measurement ◽  
Wastewater Recycling ◽  
Strong Acids ◽  
Direct And Indirect Methods

Urea is a byproduct of the urea cycle in metabolism and is excreted through urine and sweat. Ammonia, which is toxic at low levels, is converted to the safe storage form of urea, which represents the largest efflux of nitrogen from many organisms. Urea is an important nitrogen source in agriculture, is added to many industrial products, and is a large component in wastewater. The enzyme urease hydrolyzes urea to ammonia and bicarbonate. This reaction is microbially mediated in soils, hydroponic solutions, and wastewater recycling and is catalyzed in vivo in plants using native urease, making measurement of urea environmentally important. Both direct and indirect methods to measure urea exist. This protocol uses diacetyl monoxime to directly determine the concentration of urea in solution. The protocol provides repeatable results and stable reagents with good color stability and simple measurement techniques for use in any lab with a spectrophotometer. The reaction between diacetyl monoxime and urea in the presence of sulfuric acid, phosphoric acid, thiosemicarbazide, and ferric chloride produces a chromophore with a peak absorbance at 520 nm and a linear relationship between concentration and absorbance from 0.4 to 5.0 mM urea in this protocol. The lack of detectable interferences makes this protocol suitable for the determination of millimolar levels of urea in wastewater streams and hydroponic solutions.

Colorimetric determination of urea v2

2021 ◽  
Author(s):  
noah.langenfeld not provided ◽  
Laurenpayne not provided ◽  
Bruce Bugbee
Keyword(s):  
Colorimetric Determination ◽  
Diacetyl Monoxime

This protocol measures the absorbance of urea in solution in complexation with diacetyl monoxime at 520 nm and is linearly proportional to concentration up to 5 mM urea.

scholarly journals Second-Derivative Spectrometric Determination of Urea in Milk Using the Diacetyl Monoxime Reagent

2010 ◽  
Vol 93 (2) ◽  
pp. 485-491 ◽  
Author(s):  
Steven A Nyanzi ◽  
Maureen Isiko ◽  
Francis Kateregga ◽  
Wolfgang Schwack
Keyword(s):  
Correlation Coefficients ◽  
Colorimetric Determination ◽  
Second Derivative ◽  
Linear Calibration ◽  
Colored Complex ◽  
Spectral Bands ◽  
Sensitivity And Selectivity ◽  
Diacetyl Monoxime ◽  
Second Derivative Method

Abstract The application of derivative spectrometry to resolve overlapping spectra and improve the sensitivity and selectivity of the colorimetric determination of urea in milk using diacetyl monoxime is presented. With first-derivative (1D) spectrometry, the max of the colored complex was established to be 525 nm. The absorption band at max 525 nm in normal absorption (0D) spectrometry was resolved into three clearly distinct spectral bands with minima at 497, 530, and 566 nm with second-derivative (2D) spectrometry. With the second-derivative (2D530) technique, the depth of the trough of the strongest signal at 530 nm was used to determine urea in milk samples. Linear calibration curves for urea were obtained over a concentration range of 0.21.4 mg/L, with correlation coefficients greater than 0.999. The LOD and LOQ of the method were 0.01 and 0.03 mg/L, respectively. Recoveries of 99100 of spiked urea in milk with RSD values below 2.0 were obtained. The second-derivative method is simple, affordable, sensitive, and selective for the determination of urea in milk.

scholarly journals In vivo determination of body composition by tritium dilution in the rat

1979 ◽  
Vol 41 (3) ◽  
pp. 625-628 ◽  
Author(s):  
Nancy J. Rothwell ◽  
M. J. Stock
Keyword(s):  
Body Water ◽  
Female Rats ◽  
Indirect Methods ◽  
Male And Female ◽  
Male And Female Rats ◽  
Significant Difference ◽  
Total Body ◽  
Direct And Indirect Methods

Total body water was determined in vivo by tritium dilution in thirty-two male and female rats. Body water obtained by tritium dilution and body fat calculated from this value correlated significantly with body water and fat obtained by analysis (r 0.985, 0.855 respectively). There was no significant difference between values for fat assessed by the direct and indirect methods.

The colorimetric determination of cyanate ion with hydroxylamine-diacetyl monoxime

1974 ◽  
Vol 23 (9) ◽  
pp. 1071-1073
Author(s):  
Keiichiro ISHII ◽  
Takeji IWAMOTO ◽  
Kazuhiko YAMANISHI
Keyword(s):  
Colorimetric Determination ◽  
Diacetyl Monoxime

A New Simple Semimicro Method for Colorimetric Determination of Urea

1963 ◽  
Vol 9 (1) ◽  
pp. 102-108 ◽  
Author(s):  
J J Coulombe ◽  
L Favreau
Keyword(s):  
Acid Medium ◽  
Rapid Method ◽  
Room Temperature ◽  
Colorimetric Determination ◽  
Red Color ◽  
Color Complex ◽  
Blood Filtrate ◽  
Diacetyl Monoxime

Abstract A new simple and rapid method for quantitative semimicro determination of blood urea is presented. Diacetyl monoxime and thiosemicarbazide form in acid medium with urea a red color complex with a maximum adsorption at 530 mµ stable at room temperature and requiring 0.2 ml. of 1:10 blood filtrate.

A Method for the Colorimetric Determination of β-Glucuronidase in Urine, Serum, Tissue; Assay of Enzymatic Activity in Health and Disease

1959 ◽  
Vol 36 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Julius A. Goldbarg ◽  
Esteban P. Pineda ◽  
Benjamin M. Banks ◽  
Alexander M. Rutenburg
Keyword(s):  
Enzymatic Activity ◽  
Colorimetric Determination ◽  
Health And Disease ◽  
Urine Serum

A Molecular Approach to Immunoscintigraphy: A Study of the T-Antigen Conformation on the Surface of Tumors

1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Cell ◽  
T Antigen ◽  
Human Carcinomas ◽  
Animal Tumor ◽  
Synthetic Antigens

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.

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