Results 201 to 210 of about 167,532 (264)

Colorimetric Assay of Levodopa

Journal of Pharmaceutical Sciences, 1972
Abstract A new colorimetric assay method for levodopa, based on the reaction with isonicotinic acid hydrazide in alkaline medium, is reported. Data on precision, accuracy, and specificity are also given. The method, owing to its simplicity, is particularly suited for the routine purity control of levodopa.
N, Maggi, A, Cometti
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Colorimetric assay of digitoxin

Journal of the American Pharmaceutical Association (Scientific ed.), 1948
A colorimetric method in which sodium beta-naphthoquinone-4-sulfonate (purified) is reacted with digitoxin in alkaline solution to form a purple color is proposed for the determination of digitoxin. The purple color quickly reaches a maximum and fades, but the addition of acetic acid at the time of maximum development changes the color to yellow and ...
A T, WARREN, F O, HOWLAND, L W, GREEN
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Colorimetric Assay of Epinephrine

Journal of Pharmaceutical Sciences, 1974
A new colorimetric assay method for epinephrine, based on the reaction with thiosemicarbazide in alkaline medium, is presented. Beer's law is followed in the range of 25–300 μg. Data on precision, accuracy, and specificity are included. A special calculation is adopted in the presence of norepinephrine.
R B, Salama, S K, Khalil
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Colorimetric Assay of Nystatin

Journal of Pharmaceutical Sciences, 1963
A colorimetric method to assay nystatin both as powder and in pharmaceutical preparations is described. Nystatin is hydrolyzed with sodium hydroxide; the yellow color produced is extracted from a buffered solution into chloroform and measured colorimetrically. Comparison with microbiological assay is shown in a degradation experiment.
J C, CHANG, A B, HONIG, A T, WARREN, S, LEVINE   +3 more
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Colorimetric Assay of Disulfiram

Journal of Pharmaceutical Sciences, 1973
A quantitative assay for disulfiram was developed based on color formation during the interaction of disulfiram, ethanol, and cyanide. A linear curve is obtained over a wide range of disulfiram concentrations. Metabolites of disulfiram do not interfere in this assay.
R, Fried, A N, Masoud, F M, Klein
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Detection of opines by colorimetric assay

Analytical Biochemistry, 1987
A colorimetric procedure for confirming the presence of arginine-derived opines (nopaline and octopine) in plant tissue extracts is described. Those materials are widely used as markers of plant cell transformation and tumorigenesis mediated by the tumor-inducing plasmids of Agrobacterium tumefaciens.
N S, Yang, S G, Platt, P, Christou
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An easy colorimetric assay for glycosyltransferases

Biochemistry (Moscow), 2010
Glycosyltransferases are involved in biosynthesis of both protein-bound and non-bound glycans that have multiple and important biological functions in all species. A variety of methods for assaying glycosyltransferase activity have been developed driven by the specific interests and type of information required by researchers.
Rui, Shen, Shuai, Wang, Xiaofeng, Ma, Junyang, Xian, Jing, Li, Lianwen, Zhang, Peng, Wang   +6 more
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Colorimetric assay for cellular transglutaminase

Analytical Biochemistry, 1989
A colorimetric assay for cellular transglutaminase using 5-(biotinamido)pentylamine and polyvinylidine difluoride membranes for crude cellular preparations and purified enzyme has been developed. The biotinpentylamine substrate was incorporated into N,N-dimethylcasein by transglutaminase, the biotinylated products were adsorbed onto the membrane disks ...
W M, Jeon, K N, Lee, P J, Birckbichler, E, Conway, M K, Patterson   +4 more
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An improved colorimetric assay for polyols

Analytical Biochemistry, 1977
Abstract A new assay for polyols was developed that minimizes interference by sugars. It is based on oxidation of alditols to formaldehyde by acidic periodate, reduction of the excess periodate with l -rhamnose, and a short-time determination of the formaldehyde with the Nash reagent. When glycerol was added to various crude biological materials and
S H, Bok, A L, Demain
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Colorimetric and titrimetric assay of isoniazid

Journal of Pharmaceutical and Biomedical Analysis, 1992
Two methods are proposed for the determination of isoniazid in pure form or in tablets. In the first method chlorpromazine hydrochloride, when treated with 2-iodoxybenzoic acid as an oxidant in 50% w/v o-phosphoric acid solution, is oxidized to chlorpromazine free radical which absorbs at 530 nm.
A M, el-Brashy, S M, el-Ashry
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