A colorimetric method for the quantitative measurement of rancidity

The Analyst ◽  
1935 ◽  
Vol 60 (713) ◽  
pp. 515
Author(s):  
Magnus Pyke
Keyword(s):  
Quantitative Measurement ◽  
Colorimetric Method

A COLORIMETRIC METHOD FOR MEASURING INDICAN

1960 ◽  
Vol 38 (3) ◽  
pp. 253-262 ◽  
Author(s):  
A. M. Marko ◽  
F. B. Reynolds
Keyword(s):  
Potassium Salt ◽  
Sodium Acetate ◽  
Quantitative Measurement ◽  
Colorimetric Method ◽  
Urine Samples ◽  
Review Of The Literature ◽  
Optimum Conditions ◽  
Qualitative Test ◽  
Colored Compound ◽  
Colored Reaction Product

A qualitative test for indican (indoxyl-O-sulphate, usually as the potassium salt) has been adapted for the quantitative measurement of indican. The method involves the condensation of indican and p-dimethylaminobenzaldehyde in the presence of acid to yield an orange-colored compound. When an excess of sodium acetate is added, the orange-colored reaction product is converted to a cherry-red derivative. The effects of time, acids, temperature, and concentration of reagents on the reaction have been studied and optimum conditions have been selected to obtain a standard curve.Unsatisfactory analytical results are obtained when this method is applied directly to urine samples and a method for the quantitative elution of indican from charcoal columns has, therefore, been devised. With this modification quantitative recoveries have been achieved with indican alone and with indican added to urine samples.In addition a review of the literature pertaining to indican measurement and indigoid pigments is presented.

scholarly journals The inhibition of N-acetyl-β-d-glucosaminase by the (1→4)- and (1→5)-lactones of N-acetylglucosaminic acid

1970 ◽  
Vol 119 (2) ◽  
pp. 303-306 ◽  
Author(s):  
T. E. Couling ◽  
R. Goodey
Keyword(s):  
Paper Chromatography ◽  
Relative Stability ◽  
Quantitative Measurement ◽  
Colorimetric Method ◽  
Countercurrent Distribution

The inhibition of N-acetyl-β-d-glucosaminase activity by 2-acetamido-2-deoxy-d-gluconolactone was examined. Separation of the (1→4)- and (1→5)-lactones was achieved by using paper chromatography or countercurrent distribution and identification was obtained by examination of the relative stability of the components of separated material. Quantitative measurement of the two lactones was by kinetic titration or by a colorimetric method based on their reaction with hydroxylamine. It was shown that only the (1→5)-lactone acted as an inhibitor of N-acetyl-β-d-glucosaminase.

Colorimetric Method for the Determination of Starch in Tobacco

1972 ◽  
Vol 55 (1) ◽  
pp. 209-213
Author(s):  
A J Sensabaugh ◽  
Kenneth L Rush
Keyword(s):  
Acid Treatment ◽  
Quantitative Measurement ◽  
Starch Content ◽  
Colorimetric Method ◽  
Colored Complex ◽  
Iodine Complex ◽  
Mesh Screen ◽  
Colorimetric Data ◽  
Tobacco Sample

Abstract A method is presented for extracting and determining the starch content of tobacco. Dried tobacco is ground to pass a 60 mesh screen, interfering colored materials are removed from the tobacco by a methanol-water extraction, and the starch is extracted from the tobacco by a perchloric acid treatment. Final quantitative measurement of the starch is made on a colored starch–iodine complex. The absorbance of this colored complex at 600 nm is proportional to the concentration of the starch in solution and can be related to the starch content of the original tobacco sample. Also included is a procedure for the isolation of pure tobacco starch. Such material was prepared for use as a calibration standard needed for the calculation of starch content of tobacco samples from the colorimetric data.

A COLORIMETRIC METHOD FOR MEASURING INDICAN

1960 ◽  
Vol 38 (1) ◽  
pp. 253-262
Author(s):  
A. M. Marko ◽  
F. B. Reynolds
Keyword(s):  
Potassium Salt ◽  
Sodium Acetate ◽  
Quantitative Measurement ◽  
Colorimetric Method ◽  
Urine Samples ◽  
Review Of The Literature ◽  
Optimum Conditions ◽  
Qualitative Test ◽  
Colored Compound ◽  
Colored Reaction Product

A qualitative test for indican (indoxyl-O-sulphate, usually as the potassium salt) has been adapted for the quantitative measurement of indican. The method involves the condensation of indican and p-dimethylaminobenzaldehyde in the presence of acid to yield an orange-colored compound. When an excess of sodium acetate is added, the orange-colored reaction product is converted to a cherry-red derivative. The effects of time, acids, temperature, and concentration of reagents on the reaction have been studied and optimum conditions have been selected to obtain a standard curve.Unsatisfactory analytical results are obtained when this method is applied directly to urine samples and a method for the quantitative elution of indican from charcoal columns has, therefore, been devised. With this modification quantitative recoveries have been achieved with indican alone and with indican added to urine samples.In addition a review of the literature pertaining to indican measurement and indigoid pigments is presented.

scholarly journals Spectrophotometric quantification of dolutegravir based on redox reaction with Fe3+/1,10-phenanthroline

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Swathi Naraparaju ◽  
Durai Ananda Kumar Thirumoorthy ◽  
Sunitha Gurrala ◽  
Asra Jabeen ◽  
Pani Kumar D. Anumolu
Keyword(s):  
Redox Reaction ◽  
Quantitative Measurement ◽  
Colorimetric Method ◽  
Dosage Forms ◽  
Control Analysis ◽  
Colored Complex ◽  
Pharmaceutical Dosage Form ◽  
Pharmaceutical Dosage Forms ◽  
Quality Control Analysis

Abstract Background A simple and sensitive spectrophotometric method was developed for the quantitative measurement of dolutegravir in pure form and pharmaceutical formulation. The present method was based on redox reaction between dolutegravir and ferric chloride, which upon complexation with 1,10-phenanthroline formed an orange-colored complex that showed absorption maximum at 520.0 nm. Results The developed method obeyed linearity in the concentration range of 40.00–140.00 μg/mL. The method was also validated as per International Council for Harmonization guidelines and the results were within acceptance values. The validated method was employed for the determination of dolutegravir in pharmaceutical dosage form and the percentage assay value was found to be 102.5, which is in agreement with its label claimed. Conclusion The developed redox-based colorimetric method could be used in the routine quality control analysis of dolutegravir present in various pharmaceutical dosage forms.

A quantitative image analysis method for the determination of cocontinuity in polymer blends

1993 ◽  
Vol 51 ◽  
pp. 894-895
Author(s):  
William A. Heeschen
Keyword(s):  
Image Analysis ◽  
Polymer Blends ◽  
Quantitative Measurement ◽  
Morphological Evolution ◽  
Phase Ratio ◽  
Irregular Shapes ◽  
Quantitative Image ◽  
Discrete Domains ◽  
A Domains

Two new morphological measurements based on digital image analysis, CoContinuity and CoContinuity Balance, have been developed and implemented for quantitative measurement of morphology in polymer blends. The morphology of polymer blends varies with phase ratio, composition and processing. A typical morphological evolution for increasing phase ratio of polymer A to polymer B starts with discrete domains of A in a matrix of B (A/B < 1), moves through a cocontinuous distribution of A and B (A/B ≈ 1) and finishes with discrete domains of B in a matrix of A (A/B > 1). For low phase ratios, A is often seen as solid convex particles embedded in the continuous B phase. As the ratio increases, A domains begin to evolve into irregular shapes, though still recognizable as separate domains. Further increase in the phase ratio leads to A domains which extend into and surround the B phase while the B phase simultaneously extends into and surrounds the A phase.

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