Colorimetric Determination of Thymol and Eugenol in Volatile Oils

1978 ◽  
Vol 61 (1) ◽  
pp. 169-171
Author(s):  
Mohamed A Korany ◽  
Nabil Abdel-Salam ◽  
Mohamed Abdel-Salam
Keyword(s):  
Acetic Acid ◽  
Sodium Hydroxide Solution ◽  
Colorimetric Method ◽  
Aqueous Acetic Acid ◽  
Colorimetric Determination ◽  
Clove Oil ◽  
Volatile Oils ◽  
Thyme Oil ◽  
Yellow Color

Abstract A colorimetric method for determining thymol and eugenol in volatile oils is presented. Thymol and eugenol are reacted with sodium cobaltinitrite in aqueous acetic acid. The yellow color produced is measured at 330 and 370 nm in chloroform, and at 396 and 450 nm in sodium hydroxide solution for thymol and eugenol, respectively. The method is applied to the assay of thyme oil (thymol type) and clove oil. The results obtained are reasonably reproducible with a coefficient of variation less than 2%.

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%.

Sodium Cobaltinitrite as a Reagent for Determining Some Phenolic Drugs

1978 ◽  
Vol 61 (5) ◽  
pp. 1113-1117
Author(s):  
Abdel-Aziz M Wahbi ◽  
Hassan Abdine ◽  
Mohamed Korany ◽  
Mohamed H Abdel-Hay
Keyword(s):  
Acetic Acid ◽  
Sodium Hydroxide ◽  
Coefficient Of Variation ◽  
Maximum Absorption ◽  
Aqueous Acetic Acid ◽  
Salbutamol Sulfate ◽  
Tablet Form ◽  
Yellow Color ◽  
Phenolic Drugs

Abstract Dichlorophen, oxyphenbutazone, phenazone, methyldopa, isoprenaline sulfate, and salbutamol sulfate are reacted with sodium cobaltinitrite in aqueous acetic acid. The yellow color is measured at 365, 320, 320, 330, 425, and 325 nm in aqueous acetic acid, respectively, and at 445, 380, 375, 345, 325, and 412 nm in sodium hydroxide, respectively. The reaction product is extractable with CHC13, with a maximum absorption at 370 nm for dichlorophen, 355 nm for phenazone, and 325 nm for oxyphenbutazone. The method is applied to the determination of these drugs in tablet form. The results obtained are reasonably reproducible with a coefficient of variation less than 2%.

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.

Notizen: Improved 2,4-Dinitrophenylhydrazine, Thin Layer Chromatography Methods for the Determination of Micro- and Macroamounts of Ascorbic Acid

1974 ◽  
Vol 29 (11-12) ◽  
pp. 777-780 ◽  
Author(s):  
A. Navon ◽  
H. Z. Levinson
Keyword(s):  
Acetic Acid ◽  
Vitamin C ◽  
Thin Layer ◽  
Condensation Reaction ◽  
Dehydroascorbic Acid ◽  
Previous Method ◽  
Aqueous Acetic Acid ◽  
Tlc Plates ◽  
Layer Chromatography

Microamounts of vitamin C could be readily determined in 20 μl-samples using the 2,4-dinitrophenylhydrazine method together with separation by thin layer chromato­graphy. The condensation reaction was carried out for 5 min at 100 °C on a glass fibre disc. Purification of vitamin C hydrazones was accomplished by repeated separation on TLC plates. An aqueous solution of 65% acetic acid was em­ployed to dissolve the vitamin C hydrazones, providing maxi­mal absorbance at 500 nm. The minimum amount detectable by this method is 0.4 μg of dehydroascorbic acid. The macrodetermination of vitamin C was improved by simpli­fying a previous method and employing 65% aqueous acetic acid as a solvent for the hydrazones.

Titrimetric Determination of Iodine-Bromine Numbers of Some Edible Oils Using Three N-Chloroimides

1987 ◽  
Vol 70 (4) ◽  
pp. 762-763
Author(s):  
Narayanan Jayasree ◽  
Parameswaran Indrasenan
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Solid State ◽  
Palm Olein ◽  
Edible Oils ◽  
Aqueous Acetic Acid ◽  
Acetic Acid Medium ◽  
Back Titration ◽  
Titrimetric Determination

Abstract Three simple titrimetric methods have been developed to determine iodine-bromine numbers of some edible oils, such as coconut, gingelly, groundnut, mustard, olive, palm olein, and sunflower, using 3 N-chloroimides. The 3 N-chloroimides are N-chlorophthalimide, N-chlorosuccinimide, and N-chlorosaccharin, all of which have recently been developed as potential oxidimetric titrants for use in aqueous acetic acid medium. The proposed excess back-titration methods have advantages over existing methods in terms of ease of extraction into aqueous acetic acid layer, shorter reaction time of NCSA method, and stability of N-chloroimides in solid state.

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 Oxyphenisatin and Oxyphenisatin Diacetate in Pharmaceutical Preparations

1964 ◽  
Vol 47 (4) ◽  
pp. 688-692
Author(s):  
Antoine Major
Keyword(s):  
Aqueous Solution ◽  
Organic Solvent ◽  
Silver Nitrate ◽  
Sodium Hydroxide ◽  
Column Chromatography ◽  
Sodium Hydroxide Solution ◽  
Pharmaceutical Preparations ◽  
Colorimetric Determination ◽  
Hydroxide Solution

Abstract A method is described which will quantitatively determine 0.1 mg oxyphenisatin or the diacetate in various pharmaceutical preparations. After removal of interferences by organic solvent extractions from aqueous solution and partition column chromatography, the reaction of oxyphenisatin (diacetate) with silver nitrate in alcoholic sodium hydroxide solution produces a violet solution, which follows Beer’s law (1—15 μg per ml). The method was satisfactorily applied to the assay of commercial tablets, liquids, and powders with recoveries, as per cent found of declared, in the range 95—101%.

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.

scholarly journals Determination of Sulfonamides in Edible Salmon Tissue by Liquid Chromatography with Postcolumn Derivatization and Fluorescence Detection

1997 ◽  
Vol 80 (4) ◽  
pp. 751-755 ◽  
Author(s):  
Theresa A Gehring ◽  
Larry G Rushing ◽  
Harold C Thompson
Keyword(s):  
Acetic Acid ◽  
Liquid Chromatography ◽  
Fluorescence Detection ◽  
Coho Salmon ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Aqueous Acetic Acid ◽  
Postcolumn Derivatization

Abstract Fourteen sulfonamides—sulfanilamide, sulfadiazine, sulfathiazole, sulfapyridine, sulfam- erazine, sulfamethazine, sulfamethizole, sulfamethoxypyridazine, sulfachloropyridazine, sulfamonomethoxine, suļfadoxine, sulfamethoxazole, sulfadimethoxine, and sulfaquinoxoline—residues of which could be found in aquacultured species, were separated in <25 min by reversed-phase (C18) liquid chromatography (LC) with gradient elution. Analytes were extracted from edible salmon tissue (muscle and adhering skin) with acetonitrile—2% aqueous acetic acid, isolated with 2 liquid-liquid partitionings, and derivatized with fluorescamine after eluting from the column. The derivatives were detected by fluorescence. Recoveries (n = 4) from coho salmon fortified with sulfonamides at 5,10, and 20 ng/g tissue averaged 79.7± 7.3, 84.6 ± 7.7, and 88.2 ± 7.1%, respectively. Limits of quantitation were 5 ng/g tissue, for sulfanilamide, sulfamethoxypyridazine, and sulfaquinoxoline and 1 ng/g tissue for the remaining sulfonamides.

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