Color reaction

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

Ngf action enhancer

Abstract: PURPOSE:To obtain a new compound having an NGF action enhancing effect and useful, eg as a medicine for improving dementia or sequella of cerebral hemorrhage CONSTITUTION:A compound of the formula (R is CH2COCH2CH2OH or CH2 CH20H) In addition, NG-242 (R is CH2COCH2CH2OH) has following physical properties: SI mass spectrum: 472 (M+H) ; molecular weight: 471; ultraviolet absorption spectrum (in methanol solution): lambdamax 214nm (g: 41800), 258nm (epsilon=9600), 306 nm (g : 3300); IR spectrum: as shown in the figure; solvent solubility: soluble in methanol, ethanol and acetone, sparingly soluble in n-hexane and benzene and insoluble in water; color reaction: positive to H2SO2, I2 or FeCl3 and negative to ninhydrin reaction; classification of basic, acidic or neutral: acidic; color of substance; white powder In addition, the compound of the formula can be obtained by aerobically culturing Stachybotrys-parvispora- F-4708 (FERM-P-12660) in a culture medium containing nutritive substances

Spectrophotometric Determination of Trace Thallium with Cadion 2B Using Polyurethane Foam as an Adsorption _ separating Material

Abstract: It was investigated that the color reaction of thallium with Cadion 2B in the NH3-NH4Cl medium at pH 11.5～12.5 with Triton X-100. Thallium(Ⅲ) and Cadion 2B form a 1∶4(molar ratio)red complex with apparent molar absorptivity 9.3×104 L·mol-1·cm-1 at 500 nm of detection wavelength. The coloration of the reaction is completed for an instant at room temperature and the color is stable at least for 12 h. Beer's law is obeyed in the mass concentration range of 0～800 μg/L for thallium. A method for the determination of trace amount of thallium by spectrophotometry was established using polyurethane foam as an adsorption _ separating material. The proposed method is rapid and accurate and has been applied to determine trace amounts of thallium in geological samples in aqueous solution with recoveries of 97.0%～106%. The relative standard deviations(n=5) are less than 4.1%. The results obtained are in good agreement with the values obtained by AAS.

Method for analysis of urea

Abstract: A METHOD FOR DETERMINING UREA COMPRISING THE INCUBATION OF THE SAMPLE CONTAINING UREA IN A BUFFERED SOLUTION CONTAINING UREASE AND NITROPRUSSIDE, FOLLOWED BY THE ADDITION OF A SOURCE OF PHENATE ION AND A SOURCE OF HYPOCHLORITE ION IN AN ALKALINE MEDIUM TO PRODUCE A COLOR REACTION.