Color reaction

About: Color reaction is a research topic. Over the lifetime, 1194 publications have been published within this topic receiving 19579 citations.

Beet/sugarcane antioxidant composition

Abstract: PROBLEM TO BE SOLVED: To obtain an excellent antioxidant by forming a beet/sugarcane antioxidant composition which has specified physicochemical properties such as elemental analysis values, mol.wt., m.p., organic content, solubility in solvents, color reaction, discrimination among basicity, acidity and neutrality, color, shape, antioxidant properties and ultraviolet-absorbing capability. SOLUTION: This composition has such physicochemical properties that the elemental analysis values of C, H and N are 47.8%, 6.3% and 9.8%, respectively; the mol.wt. is 500-50,000; the m.p. is 300 deg.C or higher; it does not change even at 300 deg.C or higher; the organic content is 90-95%; it is completely soluble in water, easily soluble in an aqueous 50% ethanol solution, hardly soluble in an aqueous 75% ethanol solution and insoluble in ethanol; it has such color reactions that the ninhydrin reaction is + and the phenol-sulfuric acid reaction is +; its 1% aqueous solution is brown and clear; it has a pH of 5.0-6.5; it is a brown powder; and it exhibits strong antioxidant properties and ultraviolet absorption capability. This composition is prepared by removing low-mol.-wt. substances from a waste liquid separated in the chromatography step of a beet/cane sugar production plant.

The Color Reaction between Chromium(III) Ion and Potassium Ferrocyanide

Abstract: The observation of the orange-coloring reaction between potassium ferrocyanide and the chromium(III) ion on filter paper and its application in the paper chromatographical analysis of the chromium(III) ion has been reported on previously by the present authors. The color reaction has now been observed in an aqueous solution as well and studied in relation to the reaction temperature, the reaction time, the characteristic absorption, the species of chromium(III) salts, the chromium(III) ion concentration, the pH level, and the presence of an acetic acid buffer, by measuring the absorption spectra of the reaction solutions. The recommended conditions for getting a satisfactory color reaction and a suitable wavelength for the measurement of this color reaction have been presented.

Sensitive and Simple Methods for Determination of l-Lysine with l-Lysine α-Oxidase

Abstract: l-Lysine could be determined satisfactorily with a new fungal enzyme, l-Iysine α-oxidase (EC 1.4.3). The method consists of the oxidative deamination of l-Iysine with l-lysine α-oxidase and the spectrophotometric determination of one of the reaction products: α-keto-e-aminocaproate, its intramolecular dehydrated form, Δ1-piperideine-2-carboxylate or hydrogen peroxide. The method on the basis of the color reaction of hydrogen peroxide formed from l-lysine with 4-aminoantipyrine and phenol in the presence of peroxidase was most sensitive and simple. The method could be used for the direct assay of l-lysine levels in serums from several animals without pretreatments.