Colorimetric determination of sterols in vegetable oils with chloramine T and sulfuric acid reagent

1980 ◽  
Vol 57 (8) ◽  
pp. 250-251 ◽  
Author(s):  
K. L. Ahuja ◽  
K. L. Bajaj
Keyword(s):  
Sulfuric Acid ◽  
Vegetable Oils ◽  
Colorimetric Determination ◽  
Acid Reagent ◽  
Chloramine T

Colorimetric Determination of Ethinyl Estradiol in Oral Contraceptive Formulations

1974 ◽  
Vol 57 (3) ◽  
pp. 747-751
Author(s):  
John Y P Wu
Keyword(s):  
Sulfuric Acid ◽  
Oral Contraceptive ◽  
Ethinyl Estradiol ◽  
Chromatographic Column ◽  
Colorimetric Determination ◽  
Color Formation ◽  
Coefficients Of Variation ◽  
Label Claim ◽  
Acid Reagent

Abstract Ethinyl estradiol in oral contraceptive formulations is separated from the sample on a chromatographic column prior to color formation with methanol-sulfuric acid reagent directly in the chloroform-isooctane eluate. Collaborative results on 3 commercial tablet samples averaged 93.93, 98.69, and 98.50% of label claim. The standard deviations and coefficients of variation were 2.61, 2.39, and 2.82, and 2.77, 2.43, and 2.86%, respectively. The method has been adopted as official first action.

Colorimetric Determination of Ethinyl Estradiol in Oral Contraceptive Formulations

1974 ◽  
Vol 57 (3) ◽  
pp. 756-760
Author(s):  
John Y P Wu
Keyword(s):  
Sulfuric Acid ◽  
Oral Contraceptive ◽  
Ethinyl Estradiol ◽  
Chromatographic Column ◽  
Colorimetric Determination ◽  
Color Formation ◽  
Coefficients Of Variation ◽  
Label Claim ◽  
Acid Reagent

Abstract Ethinyl estradiol in oral contraceptive formulations is separated from the sample on a chromatographic column prior to color formation with methanol-sulfuric acid reagent directly in the chloroform-isooctane eluate. Collaborative results on 3 commercial tablet samples averaged 93.93, 98.69, and 98.50% of label claim. The standard deviations and coefficients of variation were 2.61, 2.39, and 2.82, and 2.77, 2.43, and 2.86%, respectively. The method has been adopted as official first action.

Sulfuric Acid/Hydrogen Peroxide Digestion and Colorimetric Determination of Phosphorus in Meat and Meat Products: Collaborative Study

1991 ◽  
Vol 74 (1) ◽  
pp. 22-26 ◽  
Author(s):  
David K Christians ◽  
Thomas G Aspelund ◽  
Scott V Brayton ◽  
Larry L Roberts
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Collaborative Study ◽  
Meat Products ◽  
Colorimetric Determination ◽  
Pork Sausage ◽  
Relative Standard ◽  
Significant Difference ◽  
Standard Deviations

Abstract Seven laboratories participated In a collaborative study of a method for determination of phosphorus in meat and meat products. Samples are digested In sulfuric acid and hydrogen peroxide; digestion Is complete In approximately 10 mln. Phosphorus Is determined by colorimetric analysis of a dilute aliquot of the sample digest. The collaborators analyzed 3 sets of blind duplicate samples from each of 6 classes of meat (U.S. Department of Agriculture classifications): smoked ham, water-added ham, canned ham, pork sausage, cooked sausage, and hamburger. The calibration curve was linear over the range of standard solutions prepared (phosphorus levels from 0.05 to 1.00%); levels in the collaborative study samples ranged from 0.10 to 0.30%. Standard deviations for repeatability (sr) and reproducibility (sR) ranged from 0.004 to 0.012 and 0.007 to 0.014, respectively. Corresponding relative standard deviations (RSDr and RSDR, respectively) ranged from 1.70 to 7.28% and 3.50 to 9.87%. Six laboratories analyzed samples by both the proposed method and AOAC method 24.016 (14th Ed.). One laboratory reported results by the proposed method only. Statistical evaluations Indicated no significant difference between the 2 methods. The method has been adopted official first action by AOAC.

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.

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.

Test for the Determination of Starch in Meat Food Products (Applicable for Estimation of Cereal in Sausages)

1966 ◽  
Vol 49 (2) ◽  
pp. 307-309
Author(s):  
W Glover ◽  
H Kirschenbaum ◽  
A Caldwell
Keyword(s):  
Sulfuric Acid ◽  
Perchloric Acid ◽  
Food Products ◽  
Acid Reagent ◽  
Good For

Abstract A method has been developed for determining starch in meat food products in which simple sugars are extracted from meat food products with hot 80% ethanol while starch remains. The starch residue is solublized with dilute perchloric acid, readily forms a colored derivative when heated with anthrone-sulfuric acid reagent, and is measured at 630 mμ. It was not necessary to prepare a standard dextrose curve daily. The anthrone-sulfuric acid reagent is good for 3–4 days if kept near 0.0°C.

Effects of Tomatine on the Colorimetric Determination of Cholesterol by the Zak Procedure

1967 ◽  
Vol 13 (6) ◽  
pp. 468-474 ◽  
Author(s):  
Cleamond D Eskelson ◽  
Arthur L Dunn ◽  
Clarence R Cazee
Keyword(s):  
Acetic Acid ◽  
Free Cholesterol ◽  
Colorimetric Determination ◽  
Acid Reagent ◽  
Standard Solution

Abstract The iron-acetic acid reagent used for cholesterol determinations produces a color with tomatine, which is reported to be a more specific precipitant for cholesterol. To circumvent the interferen:e of tomatine found in a cholesterol-tomatinide complex, a standard solution containing stoichiometric amounts of tomatine and cholesterol was used and proved to be reliable for the determination of free cholesterol in serum.

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.

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