Colorimetric Determination of 3-Amino-l,2,4-Triazole in Grain or Meal

1982 ◽  
Vol 65 (1) ◽  
pp. 24-27
Author(s):  
Michel Galoux ◽  
Jean-C Van Damme ◽  
Albert Bernes
Keyword(s):  
Sulfuric Acid ◽  
Limit Of Detection ◽  
Colorimetric Method ◽  
Colorimetric Determination ◽  
Colored Complex ◽  
Adsorption Desorption

Abstract This colorimetric method for the determination of 3-amino-l,2,4-triazole in grain or meal is a modification of the Storherr and Burke method. The herbicide is extracted from grain with methanol, and purified by adsorption-desorption on resin. The extract is cleaned by digestion with sulfuric acid and clarified with charcoal. The colored complex formed by coupling with N-(1-naphthyl)ethylenediammonium dichloride is measured spectrophotometrically at 455 nm. The limit of detection is 0.05 ppm.

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.

scholarly journals Self-colorimetric determination of bio-ethanol using permanganate in fermentation samples

2021 ◽  
Author(s):  
Mohamed Abdelazim
Keyword(s):  
Optical Density ◽  
Limit Of Detection ◽  
Fermentation Broth ◽  
Potassium Dichromate ◽  
Colorimetric Method ◽  
Density Difference ◽  
Neutral Medium ◽  
Colorimetric Determination ◽  
Limit Of Quantification

Abstract Without the aid of chromatographic techniques, quantification of bio-ethanol in fermentation-broth distillate becomes inconvenient. Potassium permanganate is preferable over potassium dichromate because of the latter well-known toxic properties, it is common used in ethyl alcohol determination either by visible determination of Cr(III) green optical density, a consumed Cr(VI) determination in strong acid medium by measuring band absorbance decrease at 267 nm or the unreacted Cr(VI) determination iodometrically after alcohol oxidation. Nevertheless, these titre methods arise difficulties experience analysts from multiple solutions preparation, standardization that should be carried out every day and to successful end point detection in the presence of Cr(III) green color which leads to a significant ethanol quantification error. Noteworthy permanganate-iodometry drawbacks as same as titre dichromate difficult practical procedures and multiple reagents employed. In this laboratory a self colorimetric method was developed in neutral medium as alcohol-specific oxidizing agent precludes both of its undesirable high oxidizing properties and difficult titrimetric methodologies for bio-ethanol quantification. It is based on unreacted permanganate optical density difference between a non ethanol-containing sample as a blank and ethanol-containing sample is directly proportional to the consumed permanganate amount in ethanol red-ox reaction and consequently directly proportional to ethanol content. This optical density difference versus ethanol concentration 1–6% v/v obeys Beer-Lampert law provides limit of detection, limit of quantification and correlation coefficient equal 0.17%, 0.56% and 0.999 respectively.

Colorimetric Determination of Selenium in Premixes and Supplements

1992 ◽  
Vol 75 (2) ◽  
pp. 269-271 ◽  
Author(s):  
Jeffrey A Hurlbut ◽  
Roger G Burkepile ◽  
Carolyn A Geisler
Keyword(s):  
Sulfuric Acid ◽  
Formic Acid ◽  
Coefficient Of Variation ◽  
Colorimetric Method ◽  
Colorimetric Determination ◽  
High Concentrations

Abstract A colorimetric method Is described for the determination of 100-10 000 μg selenlum/g premix. Selenium Is present in premixes as either selenite or selenate. Moderate to high concentrations of several common minerals are tolerated. The premix is briefly digested In a sulfuric acid-perchloric acidsodium molybdate mixture, boiled in 10% NaCI solution, made basic, and centrifuged. Aliquots are taken if necessary. The mixture Is then acidified with formic acid, treated with hydroxylamlne hydrochlorlde- EDTA, and complexed with 3,3 - dlamlnobenzldlne. The pH Is adjusted, and an extraction Is performed with toluene. The absorbance is measured at 420 nm. Recoveries for 100- 10 000 μg selenlum/g premix ranged from 88 to 104%, with an average of 97%. The coefficient of variation ranged from 1.6 to 6.9%, with an average of 4.2%.

Collaborative Study of a Colorimetric Determination of Nitrate in Tobacco

1969 ◽  
Vol 52 (4) ◽  
pp. 756-759
Author(s):  
C James Rosene
Keyword(s):  
Sulfuric Acid ◽  
Standard Deviation ◽  
Systematic Error ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Water Soluble ◽  
Colorimetric Determination ◽  
Error Standard Deviation

Abstract A colorimetric method for determining water-soluble nitrate in tobacco was studied by 14 laboratories on eight Burley and two cigar filler tobacco samples with nitrate levels of 0.5–2.4%. In the method, ground tobacco is extracted with water and filtered, and an aliquot is then treated with 2,4-xylenol in sulfuric acid; then the resulting 6-nitro-2,4-xylenol is removed by distillation and measured spectrophotometrically at 450 µm. Results show that, althoughthe precision standard deviation among laboratories is generally acceptable, the systematic error standard deviation is unacceptably high. This study will be continued.

scholarly journals Self-Colorimetric Determination of Bio-Ethanol Using Permanganate in Fermentation Samples

2021 ◽  
Author(s):  
Mohamed Abdelazim Abulela
Keyword(s):  
Optical Density ◽  
Limit Of Detection ◽  
Fermentation Broth ◽  
Potassium Dichromate ◽  
Colorimetric Method ◽  
Density Difference ◽  
Neutral Medium ◽  
Colorimetric Determination ◽  
Limit Of Quantification

<p>Without the aid of chromatographic techniques, quantification of bio-ethanol in fermentation-broth distillate becomes inconvenient. Potassium permanganate is preferable over potassium dichromate because of the latter well-known toxic properties, it is common used in ethyl alcohol determination either by visible determination of Cr(III) green optical density, a consumed Cr(VI) determination in strong acid medium by measuring band absorbance decrease at 267 nm or the unreacted Cr(VI) determination iodometrically after alcohol oxidation. Nevertheless, these titre methods arise difficulties experience analysts from multiple solutions preparation, standardization that should be carried out every day and to successful end point detection in the presence of Cr(III) green color which leads to a significant ethanol quantification error. Noteworthy permanganate-iodometrydrawbacks as same as titre dichromate difficult practical procedures and multiple reagents employed.</p><p>In this laboratory a self colorimetric method was developed in neutral medium as alcohol-specific oxidizing agent precludes both of its undesirable high oxidizing properties and difficult titrimetric methodologies for bio-ethanol quantification. It is based on unreacted permanganate optical density difference between a non ethanol-containing sample as a blank and ethanol-containing sample is directly proportional to the consumed permanganate amount in ethanol red-ox reaction and consequently directly proportional to ethanol content. This optical density difference versus ethanol concentration 1-6% v/v obeys Beer-Lampert law provides limit of detection, limit of quantification and correlation coefficient equal 0.17%, 0.56% and 0.999 respectively. <br></p><p><br></p>

scholarly journals Development of a Simple Colorimetric Determination of Dexamethasone

2020 ◽  
Vol 10 (02) ◽  
pp. 255-258
Author(s):  
Khalid Waleed S. Al-Janabi ◽  
Ali Khalil Mahmood ◽  
Hasan M. Luaibi
Keyword(s):  
Limit Of Detection ◽  
Cost Effective ◽  
Environmentally Benign ◽  
Colorimetric Determination ◽  
Excellent Correlation ◽  
Limit Of Quantification ◽  
Experimental Conditions ◽  
Colored Complex ◽  
Pharmaceutical Form

A simple, environmentally benign, cost-effective, and sensitive colorimetric determination for the pharmaceutical drug dexamethasone sodium phosphate (DXP) has been developed by the formation of a colored complex with fluoranil. The process was sensitive and linear over the range 1 to 40 μg/mL, excellent correlation coefficient 0.9989, recovery% 99.80 ± 1.3, limit of detection (LOD) and limit of quantification (LOQ) were 0.23 and 0.9 μg/mL, respectively, and good RSD ~1.63%. The experimental conditions were optimized after an intensive study. The approach was validated statistically for the quantification of the analyte in its pure and/or pharmaceutical form. Despite the proposed approach is selective, it still can be applied for the analysis of other pharmaceuticals.

scholarly journals Self-Colorimetric Determination of Bio-Ethanol Using Permanganate in Fermentation Samples

2021 ◽  
Author(s):  
Mohamed Abdelazim Abulela
Keyword(s):  
Optical Density ◽  
Limit Of Detection ◽  
Fermentation Broth ◽  
Potassium Dichromate ◽  
Colorimetric Method ◽  
Density Difference ◽  
Neutral Medium ◽  
Colorimetric Determination ◽  
Limit Of Quantification

<p>Without the aid of chromatographic techniques, quantification of bio-ethanol in fermentation-broth distillate becomes inconvenient. Potassium permanganate is preferable over potassium dichromate because of the latter well-known toxic properties, it is common used in ethyl alcohol determination either by visible determination of Cr(III) green optical density, a consumed Cr(VI) determination in strong acid medium by measuring band absorbance decrease at 267 nm or the unreacted Cr(VI) determination iodometrically after alcohol oxidation. Nevertheless, these titre methods arise difficulties experience analysts from multiple solutions preparation, standardization that should be carried out every day and to successful end point detection in the presence of Cr(III) green color which leads to a significant ethanol quantification error. Noteworthy permanganate-iodometrydrawbacks as same as titre dichromate difficult practical procedures and multiple reagents employed.</p><p>In this laboratory a self colorimetric method was developed in neutral medium as alcohol-specific oxidizing agent precludes both of its undesirable high oxidizing properties and difficult titrimetric methodologies for bio-ethanol quantification. It is based on unreacted permanganate optical density difference between a non ethanol-containing sample as a blank and ethanol-containing sample is directly proportional to the consumed permanganate amount in ethanol red-ox reaction and consequently directly proportional to ethanol content. This optical density difference versus ethanol concentration 1-6% v/v obeys Beer-Lampert law provides limit of detection, limit of quantification and correlation coefficient equal 0.17%, 0.56% and 0.999 respectively. <br></p><p><br></p>

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.

Collaborative Study Using a ZDBT Colorimetric Method for the Determination of Copper in Alcoholic Products

1967 ◽  
Vol 50 (2) ◽  
pp. 334-338
Author(s):  
Duane H Strunk ◽  
A A Andreasen
Keyword(s):  
Sulfuric Acid ◽  
Carbon Tetrachloride ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Good Precision ◽  
Determination Of Copper

Abstract Results are given on a collaborative study in which a zinc dibenzyldithiocarbamate (ZDBT) colorimetric method is used to measure copper in alcoholic products such as high wine, spirits, gin, whisky, brandy, rum, and wine. In this method, the sample is made ca 0.SN with sulfuric acid, and carbon tetrachloride containing 0.2% ZDBT is added. The colored copper-ZDBT complex is extracted in the carbon tetrachloride and measured at 438 mμ against a similar carbon tetrachloride extract of a blank. Data show good precision, and it is recommended that the ZDBT method be adopted as official, first action.

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