Color reaction

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

Colour reaction system with metal carboxylate or sulphonate - as developer using org ether cpd as solvent for colour former

Abstract: Colour reaction system, in which metal salts (I) of aliphatic and aromatic carboxylic and sulphonic acids are used as new developer, uses organic cpds (II) contg other gps, pref diphenoxy-diethylformal, as solvent for the colour former (III) Used in colour reaction copying papers (I) give no or only an inadequate colour reaction with (III) in the conventional solvents but give intense colours in (II) (II) are insol in water, as required for microencapsulation, are physiologically harmless and have low volatility Only 05 g (I) m2 or less is needed in the coatings, cf 4-6 g/m2 when clay minerals are employed

The determination of nitrates in colored soil extracts.

Abstract: In highly colored soil extracts, it was found impossible to determine nitrates directly by the phenoldisulphonic acid color reaction. Attempts to remove the coloring matter by oxidation or absorption were not successful. The most satisfactory method was found to be reduction of the nitrate to ammonia with Devarda's alloy in 0.1 N sodium hydroxide solution in the cold after the removal by steam distillation, of any ammonia that might be present in the extract. The ammonia formed from the nitrate was steam distilled into 0.01 N hydrochloric acid solution and determined colorimetrically by Nessler's reagent using a Klett–Summerson photoelectric colorimeter. The recovery of nitrates from the colored solutions and from standards was satisfactory. The aliquot taken for the determination should contain not more than 0.125 mgm. nitrogen as nitrate.

Stable chemical compositions containing chromogenic materials and peroxides, and method for obtaining them

Abstract: @ Chromogenic materials which react to give a color reaction when in the presence of a peroxide ROOR' decomposing to give a radical oxygen are unstable when dissolved to give working solutions for use in chromogenic reactions. Compositions containing in addition to the chromogenic material also a peroxide needed in the said reaction are also unstable, leading to premature appearance of color. Stable chemical compositions containing chromogenic materials and stable compositions containing mixtures of chromogenic materials and peroxides are described, which can be used in chromogenic reactions after having been stored for long periods of time. Also described are stabilizing chemical compositions and methods for obtaining the said stable compositions.

Si-4155b substance, its preparation and use

Abstract: NEW MATERIAL:SI-4155B substance of the formula having following physical and chemical properties; appearance: no color needle crystals; elementary analyses in %: C 64.93, H 8.90, N 0; molecular weight: 638 (calculated from FAB MS); melting point: 161.0 to 163.0 deg.C; specific rotatory power: [alpha] =+55.8 deg. (C=0.01 in methanol); solubility: soluble in benzene, ethyl acetate, chloroform, acetone, methanol, insoluble in water, n-hexane; color reaction: positive to potassium permanganate and iodine. USE:Plant growth regulator, herbicide or antimicrobial. PREPARATION:A microorganism in Streptomyces such as Streptomyces sp 4155 line (FERM P-10236) is aerobically cultured, preferably at 23 to 33 deg.C and 6 to 8pH for 4 to 6 days.