Amines in Fish Muscle: I. Colorimetric Determination of Trimethylamine as the Picrate Salt

1945 ◽  
Vol 6d (5) ◽  
pp. 351-358 ◽  
Author(s):  
W. J. Dyer
Keyword(s):  
Picric Acid ◽  
Colorimetric Method ◽  
Fish Muscle ◽  
Colorimetric Determination ◽  
Acid Reagent ◽  
Fishery Products

A sensitive accurate colorimetric method for trimethylamine determination is presented, based on the extraction with toluene of an alkaline sample containing 0.002 to 0.02 mg. trimethylamine nitrogen, and the formation of the yellow coloured picrate by mixing with a picric acid reagent. The application of the method in fishery products and effects of interfering substances have been investigated.

Colorimetric Determination of Cyanide Liberated from Apricot Kernels

1977 ◽  
Vol 60 (4) ◽  
pp. 954-956 ◽  
Author(s):  
Keith L Egli
Keyword(s):  
Hydrogen Cyanide ◽  
Steam Distillation ◽  
Sodium Hydroxide Solution ◽  
Picric Acid ◽  
Colorimetric Method ◽  
Potassium Cyanide ◽  
Colorimetric Determination ◽  
Apricot Kernels ◽  
Aoac Method

Abstract A simple colorimetric method is described for determining the quantity of hydrogen cyanide produced by the spontaneous decomposition of amygdalin in apricot kernels. The evolved cyanide is collected in sodium hydroxide solution and assayed colorimetrically by reaction with picric acid. Results for duplicate assays, 3.02 and 3.06 mg CN-/g, compare well with those obtained by AOAC method 26.115 which specifies steam distillation and silver nitrate titration; results for triplicate assays were 3.02, 3.03, and 3.08 mg CN-/g by the latter. Recovery of cyanide from potassium cyanide at a level equivalent to 243 μg CN-/g was 101.0%.

Colorimetric Determination of Hydroxyproline as Measure of Collagen Content in Meat and Meat Products: NMKL Collaborative Study

1990 ◽  
Vol 73 (1) ◽  
pp. 54-57 ◽  
Author(s):  
Kurt Kolar
Keyword(s):  
Collaborative Study ◽  
Colorimetric Method ◽  
Meat Products ◽  
Acid Oxidation ◽  
Colorimetric Determination ◽  
Mean Values ◽  
Collaborative Studies ◽  
Freeze Dried ◽  
Analytical Result

Abstract A colorimetric method for the determination of hydroxyproline as a measure of collagen in meat and meat products has been collaboratively studied in 18 laboratories. The method includes hydrolysis with sulfuric acid, oxidation with chloramine- T, and formation of a reddish purple complex with 4- dimethylaminobenzaldehyde. Five frozen and 3 freeze-dried samples were tested, ranging in content from 0.11 to 0.88% and from 0.39 to 4.0% hydroxyproline, respectively. The mean values of 2 identical samples were 0.245 and 0.251 %. The average recovery from a spiked sample was 96.1 %. The hydroxyproline content of a known sample (a mixture of 2 samples in the ratio 5:2) was calculated to 1.42%, which agrees well with the analytical result, 1.40%. In comparison with other collaborative studies, based on the ISO analytical method, the repeatability and reproducibility of this method agree well with the other results. This method was accepted as an official NMKL method by all national Committees, and has been adopted official first action by AOAC as an NMKLAOAC method.

200. The colorimetric determination of pH in milk and whey by means of the “Wulff” pH tester

1938 ◽  
Vol 9 (3) ◽  
pp. 336-338 ◽  
Author(s):  
E. Aschaffenburg
Keyword(s):  
Colorimetric Method ◽  
Cheddar Cheese ◽  
Titratable Acidity ◽  
Colorimetric Determination ◽  
Expensive Equipment ◽  
Hydrogenion Concentration ◽  
The Relationship

It has been repeatedly pointed out(1, 2, 3) that the properties of cheese during the different stages of its manufacture should be correlated with the hydrogenion concentration rather than with the titratable acidity. Little systematic work has, however, so far been carried out in this direction, except for a study of the relationship between pH and titratable acidity in Cheddar cheese by Brown & Price(4). In planning work on similar lines, it was realized that the potentiometric methods of determining pH require expensive equipment and skilled attention, so that a supplementary colorimetric method, if sufficiently accurate to indicate the major changes in pH, should appeal more strongly to the practical cheesemaker on account of its cheapness and simplicity and the ease with which the outfit can be transported.

Colorimetric Determination of Terbutaline Sulfate and Orciprenaline Sulfate via Nitrosation and Difference Spectrophotometry

1987 ◽  
Vol 70 (3) ◽  
pp. 568-571 ◽  
Author(s):  
Mohamed E El-Sadek ◽  
Hisham E Abdel Latef ◽  
Afaf A Aboul Khier
Keyword(s):  
Hydrochloric Acid ◽  
Sodium Nitrite ◽  
Colorimetric Method ◽  
Dosage Forms ◽  
Alkaline Media ◽  
Colorimetric Determination ◽  
Pharmaceutical Dosage Forms ◽  
Terbutaline Sulfate ◽  
The Difference

Abstract A colorimetric method is proposed for determination of terbutaline sulfate, orciprenaline sulfate, and their dosage forms. The suggested method depends on nitrosation of the 2 drugs by using sodium nitrite and hydrochloric acid. Addition of sodium hydroxide increases the intensity of the color developed. The difference between absorption values measured in acid and alkaline media is taken as a measure of concentration. Variables were carefully studied and optimized. Results for both compounds adhered to Beer's law over the range 2- 28 μg/mL. The method has proved to be accurate and precise for analysis of pharmaceutical dosage forms.

Colorimetric determination of potassium in whole blood, serum, and plasma.

1985 ◽  
Vol 31 (9) ◽  
pp. 1464-1467 ◽  
Author(s):  
S T Wong ◽  
J Spoo ◽  
K C Kerst ◽  
T G Spring
Keyword(s):  
Whole Blood ◽  
Colorimetric Method ◽  
Direct Determination ◽  
Ion Pair ◽  
Photometric Method ◽  
Colorimetric Determination ◽  
Two Dimensional ◽  
Subsequent Formation ◽  
Blood Specimens

Abstract This spectrophotometric method for the direct determination of potassium in serum or plasma is based on the selective complexing of potassium by a specific macrocyclic polyether, with the subsequent formation of an ion-pair with a colored anion. The colored anion is extracted into an organic solvent, clarified by centrifugation, and then measured at 415 nm. The absorbance of the chromogen varies linearly with [K+] to at least 15 mmol/L. Results of this colorimetric method (y) correlate well with the results obtained by a flame-photometric method (y = 1.04x - 0.22, r = 0.97, n = 81), with CVs ranging from 2 to 4%. We observed no interferences from lipemia, added bilirubin, or various electrolytes. We also evaluated the use of this reagent in a new automated blood analyzer developed by Abbott, a two-dimensional centrifugal system (Clin Chem 31:1457-1463, 1985). Potassium determined with this system (y) correlated well with results by flame photometry: y = 1.02x + 0.02 (r = 0.94, n = 168). With this system one can use whole-blood specimens in measuring potassium.

Colorimetric Determination of Procaine Penicillin in Mixed Feeds

1965 ◽  
Vol 48 (4) ◽  
pp. 702-704
Author(s):  
Loyal R Stone
Keyword(s):  
Chemotherapeutic Agents ◽  
Colorimetric Determination ◽  
Procaine Penicillin ◽  
Acid Reagent ◽  
Mixed Feeds ◽  
Colorimetric Procedure

Abstract Procaine penicillin is determined by a rapid colorimetric procedure based on conversion of penicillin to penicillamine which turns blue with arsenomolybdic acid reagent. The presence of other antibiotics and chemotherapeutic agents in the feed does not interfere. The method is suitable over the range 10–100 g procaine penicillin per ton of feed.

Direct Colorimetric Determination of Hippuric Acid in Urine

1972 ◽  
Vol 18 (4) ◽  
pp. 349-351 ◽  
Author(s):  
Katsumaro Tomokuni ◽  
Masana Ogata
Keyword(s):  
Hippuric Acid ◽  
Colorimetric Method ◽  
Color Reaction ◽  
Colorimetric Determination ◽  
Benzenesulfonyl Chloride

Abstract A direct colorimetric method is described for determination of hippuric acid in urine. Hippuric acid dissolved in pyridine—water (1:1) produces a color (Amax = 410 nm) when benzenesulfonyl chloride is added. With the method based on this color reaction, urinary hippuric acid follows the Beer-Lambert law up to 1 mg/ml.

Colorimetric Determination of Dillapiole in Wheat

1979 ◽  
Vol 62 (1) ◽  
pp. 203-204
Author(s):  
Swadesh K Handa
Keyword(s):  
Sulfuric Acid ◽  
Colorimetric Method ◽  
Chromotropic Acid ◽  
Colorimetric Determination ◽  
Wheat Grain ◽  
Maximum Absorbance

Abstract A rapid colorimetric method has been developed for determining residues of dillapiole (3,4-methylenedioxy-5,6-dimethoxy allyl benzene) in wheat grain. Dillapiole is reacted with sulfuric acid to liberate formaldehyde which reacts with chromotropic acid to yield a pink compound with maximum absorbance at 575 nm. The method can detect 1—15 μg residue /ml.

Colorimetric Determination of Certain Phenothiazine Drugs by Using Morpholine and Iodine-Potassium Iodide Reagents

1986 ◽  
Vol 69 (3) ◽  
pp. 513-518 ◽  
Author(s):  
Adel F Youssef ◽  
Salwa R El-Shabouri ◽  
Fardous A Mohamed ◽  
Abdel Maboud I Rageh
Keyword(s):  
Potassium Iodide ◽  
Quantitative Estimation ◽  
Colorimetric Method ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Colorimetric Determination ◽  
Reaction Products ◽  
Phenothiazine Drugs ◽  
Lower Molar

Abstract A colorimetric method was developed for the quantitative estimation of 11 phenothiazine drugs. The method is based on the interaction of unsulfoxidized drug with morpholine and iodine-potassium iodide reagents. The interaction for all studied phenothiazine drugs yields a blue product with 2 absorption maxima: one in the range of 620-640 nm with lower molar absorptivity and the other in the range of 662-690 nm with higher molar absorptivity. The color was stable for at least 10 h. The reproducibility and recovery of the method were excellent. The method was applied successfully to the analysis of various commercially available phenothiazines in different dosage forms. The results were comparable to those obtained by official procedures. The suitability of the method for detection and estimation of promethazine excreted in urine has been suggested by preliminary experiments. Reaction products have been isolated and identified.

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