Showing papers on "Color reaction published in 2019"

A Novel Chromogenic Spray Reagent for Thin-Layer Chromatographic Analysis of Paraquat and Design of an Ultra-Low-Cost Sensor for On-The-Field Detection of Viologens

Abstract: A novel spot test and a novel chromogenic reagent are reported for thin-layer chromatographic detection and identification of the popular but highly toxic herbicide paraquat. Alkaline phenylhydrazine instantly reduces paraquat to an intense purple radical cation. The reaction is sensitive and highly specific to viologens, i.e., paraquat and diquat herbicide. Surprisingly, 2,4-dinitrophenylhydrazine does not have reaction in this color test. Reaction of the two drugs containing related functional groups is also studied to check whether these drugs also react similarly. Based on this novel color reaction, a simple, ultra-low-cost filter-paper-based sensor is also designed for direct field testing of suspicious forensic samples like vomits and bottle of poison, which are usually found at a crime scene. The possible applications of the reported reaction in the field of organic qualitative analysis, clinical chemistry, and forensic medicine are also discussed.

Urine glucose content rapid detection kit based on chloroauric acid color reaction and detection method

Abstract: The invention discloses a urine glucose content rapid detection kit based on a chloroauric acid color reaction and a detection method. The kit comprises a chloroauric acid reagent bottle, a urine glucose concentration color chart and a urine glucose concentration precise quantification chart. According to the kit and the detection method disclosed by the invention, the glucose in urine serves asa reducing agent to reduce tetrachloroauric acid, at different glucose concentrations, the generated nanogold solution shows different colors; the absorption peak wavelength near 520nm of the nanogoldsolution is detected by an ultraviolet and visible spectrophotometer; the glucose content in the urine is detected rapidly, qualitatively and quantitatively according to the color development range of the nanogold solution and the correlation between the wavelength of the absorbance peak and the glucose concentration in the urine, and the detection sensitivity can reach 0.01mM.

Identification of Chemical Compounds from Karamunting Stem (Rhodomyrtus tomentosa) by Thin Layer Chromatography

Abstract: Karamunting or Kalimantan Grapes (Rhodomyrtus tomentosa) is a medicinal plant from Central Kalimantan that is easily found in shrubs. Based on hereditary experiences of the people of Central Kalimantan, karamunting can be used for the treatment of various diseases, one of which is diabetes. This study aims to identify the chemical compounds contained in the karamunting stem. The method used is thin layer chromatography with eluent n-hexane : ethyl acetate and methanol : chloroform. Besides, a color reaction was carried out to determine the group of compounds contained in the methanol extract of the karamunting stem. The TLC results show better stain separation in eluent n-hexane : ethyl acetate with the formation of four stains. Positive results are indicated by the content of phenol, saponin, flavonoid and terpenoid compounds. The existence of this group of compounds can be a clue to further research on the truth of the efficacy of karamunting.

- arsenic detecting reagent and detecting kit comprising nitro-tyrosine and method for detecting arsenic using thereof

Abstract: The present invention relates to an arsenic detection reagent and a detection kit containing nitro-tyrosine, and a method for detecting arsenic using the same. Nitro-tyrosine does not exhibit a color reaction when mixed with other metals, but only exhibits the color reaction by conducting a reaction with arsenic. Therefore, nitro-tyrosine can be used to detect arsenic, which is a poisonous substance present in water quality, food products, and the like. In addition, the method for detecting arsenic according to the present invention can determine the presence of arsenic simply by measuring the color development, thereby being very simple compared to an existing arsenic detection method.

Total nitrogen spectrophotometric method based on new chemical formulation

Abstract: The invention discloses a total nitrogen spectrophotometric method based on new chemical formulation. The method comprises the following steps: acquiring environmental water; weighing a little potassium persulfate and sodium hydroxide, and dissolving the potassium persulfate and the sodium hydroxide in water, thereby obtaining first reagent, and weighing a little resorcinol and dissolving the resorcinol in water, thereby obtaining a second reagent, and marking 98% concentrated sulfuric acid as a third reagent; adding the first reagent in the environmental water, obtaining mixed liquor, heatingup the mixed liquor, continuing heating for 15min at the temperature of 125 DEG C, then cooling to room temperature, adding the second reagent and the third reagent into the reacted mixed liquor, andperforming chemical color reaction continuously for 2min; using a spectrophotometer of which a lamp source is an LED lamp to determine absorbance, and recording a result; and calculating water sampleconcentration according to a calculation formula. In the method provided by the invention, the LED lamp light source is steady, measurement of data is fast and highly accurate, stability of single wavelength determination is excellent, interference errors are reduced, the resorcinol is added in the formulation so as to promote chemical decomposition, and the method is suitable for determination of total nitrogen of an online monitor.

Detection method for improving reaction microenvironment by using sodium dodecyl sulfate to carry out qualitative and quantitative detection on silver ions

Abstract: The invention relates to a detection method for improving a reaction microenvironment by utilizing sodium dodecyl sulfate to carry out qualitative and quantitative detection on silver ions, and the method comprises the following steps of: adding 3,3',5,5'-Tetramethylbenzidine (TMB) and sodium dodecyl sulfate (SDS) into a solution to be detected under an alkaline condition; observing whether the solution turns blue or not by adopting a visual colorimetry; realizing qualitative analysis on the silver ions in the solution to be detected; and then, determining the visible light absorbance value of the reacted solution at 397 nm by utilizing an ultraviolet spectrophotometer, and realizing quantitative detection on the silver ions in the solution to be detected. Compared with the prior art, the whole detection process is simple to operate, short in time consumption, low in cost, low in environmental requirement and easy to realize in a field rapid detection process; the detection method has stable color reaction, and no turbidity or color fading phenomenon is found within 48 hours after the solution is colored; and in addition, the method also has strong anti-interference capability.

Method for quantitatively detecting concentration of solution to be detected on the basis of color recognition

Abstract: A method for quantitatively detecting the concentration of a solution to be detected on the basis of color recognition comprises the following main steps: step S4, locating a color reaction area and information corresponding to each color block by means of an image recognition technique, and converting diffuse reflection light information into color coordinates in a specific color space; step S5, performing, by means of optical principles, equivalent calculations on the color reaction area, color block diffuse reflection information, ambient lighting, and other external factors to obtain equivalent ambient lighting; step S7, calculating a color reaction area standard color; and step S8, calculating the concentration of a solution to be detected by means of a correspondence between the color reaction area standard color and the concentration of the solution to be detected, and outputting a result. Compared to the prior art, the method for quantitatively detecting the concentration of a solution to be detected on the basis of color recognition can further correct detection errors caused by device and environmental factors, improving detection accuracy, reducing costs, and boosting applicability.