Color reaction

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

Detection method of quinolone drugs, detection reagent kit and application

Abstract: The invention discloses a detection method of quinolone drugs, a detection reagent kit and the application; in the method, methylene dichloride and hydrochloric acid are adopted to carry out pretreatment to a sample, ferric ammonium sulfate solution or ferric chloride solution is used for color reaction, according to the color development result, the detection of the quinolone drugs is realized. In the invention, mass samples to be detected are sieved preliminarily by fluorescence viewing under an ultraviolet lamp, the operation is simple and suspected positive samples can be rapidly sorted out, and then high specificity and high sensitivity color development reaction is utilized, so as to lead the detection accurate rate to reach 99 percent. The pretreatment method can eliminate effect ofcomplex and various interfering substances in the sample to be detected, and the concentration of the objective compound in the sample to be detected is improved, thereby being beneficial to observation to color reaction results in a latter period by a naked eye. The detection reagent kit in the invention can be used for detecting quinolone drugs which are mixed in cosmetics, health-care foods, disinfection products or Chinese patent drugs, and detecting the quinolone drugs and identification of the preparation.

Potassium ferrocyanide as a spectrophotometric reagent for the determination of uranium

Abstract: Potassium ferrocyanide gives a colour reaction with U(VI), which is suitable for its determination. The complex absorbs in the wavelength range of 390–397 nm. The optimum pH range for colour development was 1.5–3.5. The molar absorptivity was found to be 4.65·103 1·mol−1·cm−1. Most of the anions up to 1000 μg did not interfere. The method was made selective by extracting U(VI) first with DOSO from the mixture of interfering cations from 1–2M HNO3 medium and then determining uranium in the back-extracted solution by developing the colour with ferrocyanide. 20 μg/10 ml of U(VI) in the final solution could be satisfactorily determined within an RSD of ±2%.

Effect of Acetaldehyde on the Resorcinol Test for Fructose

Abstract: THE Seliwanoff colour reaction of ketohexoses with resorcinol and hydrochloric acid is the basis of several quantitative procedures for the determination of fructose in biological materials in which the absorbance is measured at 470 mµ1, 480 mµ2, 490 mµ3, 510 mµ4, 520 mµ5, and 540 mµ6. Roe reported that the addition of ethanol5,7 or acetic acid5 to the reaction mixture has the effect of increasing the absorbance of the coloured product at 520 mµ. The cause of the effect produced by these solvents is obscure. Roe suggested that the dehydrating conditions of the reaction were improved by introducing ethanol7 and that the hydrolytic properties of the reagent were improved by the addition of acetic acid5. While some workers have noted that the quality of the solvents affected the absorbance at 480 mµ2,8 and the absorption spectrum9, the fact that impurities in these solvents may be largely responsible in some cases for the effect attributed to the solvents themselves seems to have passed unnoticed. In this communication we wish to direct attention to the effect produced by acetaldehyde, an impurity in commercial acetic acid10 and ethanol11, on the colour formation in the resorcinol test.