Showing papers on "Color reaction published in 2007"
TL;DR: The method was applied to the determination of uranium(VI) in tap water, waste-water and well water samples and the interference effect of some anions and cations was also tested.
90 citations
TL;DR: A novel bistriazene, 4,4'-bis(3-(4-phenylthiazol-2-yl)triazenyl)biphenyl (BPTTBP), and its highly sensitive color reaction with Hg(2+), which has been successfully applied to spectrophotometric determination of mercury in waste water samples.
18 citations
TL;DR: The proposed method was successfully applied to the determination of beryllium in real water samples and the analytical characteristics of the method obtained, limit of detection, linear range and preconcentration factor were obtained.
Abstract: A cloud-point extraction process using a mixed micelle of the cationic surfactant cetyl pyridinium chloride (CPC) and non-ionic surfactant Triton X-114 to extract beryllium from aqueous solutions was investigated. The method is based on the color reaction of beryllium with Chrome Azurol S (CAS) in acetate buffer and the mixed micelle-mediated extraction of the complex. This complex was concentrated in a surfactant-rich phase after separation. The optimal extraction and reaction conditions (e.g. pH, reagent and surfactant concentrations, temperature, incubation and centrifuge times) were evaluated and optimized. Under the optimized conditions, the analytical characteristics of the method (e.g. limit of detection, linear range and preconcentration factor) were obtained. Linearity was obeyed in the range of 0.30 - 18 ng mL(-1) of beryllium and the detection limit of the method was 0.05 ng mL(-1). The interference effect of some cations and anions was also studied. The proposed method was successfully applied to the determination of beryllium in real water samples.
16 citations
TL;DR: The obtained results were favorably compared to flame atomic absorption spectrometry (FAAS) used as a reference method and the chemical and instrumental variables affecting the determination were studied and optimized.
10 citations
Patent•
22 Aug 2007
TL;DR: In this paper, a method to test Sildenafil citrate and its ramifications is presented, which is based on color reaction of test sample with bismuth potassium iodide, silico-tungstic acid and Hager's reagent.
Abstract: The invention discloses a method to test Sildenafil citrate and its ramifications. It contains steps: (1) Color reaction. Make color reaction of test sample with bismuth potassium iodide, silico-tungstic acid and Hager's reagent to observe result. (2) Result estimation. If above three color reactions appear deposit, there are Sildenafil citrate and its ramifications in test samples. If just one, two or none color reaction appear deposit, there is no Sildenafil citrate and its ramifications in test samples. The method has merits of quick, simple, strong property, high accuracy, extensive application and testing range.
9 citations
TL;DR: A new method for the analysis of ubiquinones in various samples was developed using an HPLC system with postcolumn derivatization because of its high selectivity for ubiquinone detection.
7 citations
Patent•
22 Aug 2007
TL;DR: In this article, a method to detect Tadalafil and its derivative is presented. But the method adopts special Flood reaction of Tadalaffil is for testing, which has merits of quick, simple, high sensitivity and strong property etc.
Abstract: The invention discloses a method to detect Tadalafil and its derivative: (1) Color reaction. Make color reaction by adding vitriol solution of sodium molybdate. (2) Result estimation. If color reaction presents blue violet, there are Tadalafil and its derivative in test samples. The method adopts special Flood reaction of Tadalafil is for testing, which has merits of quick, simple, high sensitivity and strong property etc.
6 citations
TL;DR: In this article, the reaction of retinoids (retinol, retinyl acetate, and anhydro retinol) with Bronsted acids was studied as a model system for the Carr-Price reaction.
Abstract: The reaction of retinoids (retinol, retinyl acetate and anhydroretinol) with Bronsted acids was studied as a model system for the Carr–Price reaction. The anhydroretinylic cation was characterised by VIS and 2D NMR spectroscopy, including an estimate of the charge distribution and region of bond inversion, observed in a mixture of identified E/Z isomers. Products obtained by quenching with NaOMe–MeOH were identified by HPLC and MS. The classical Carr–Price reaction between retinol (vitamin A) and the Lewis acid SbCl3 in saturated chloroform solution was reinvestigated by VIS, NMR, EPR, dynamic light scattering and chemical quenching. Whereas product instability and failure to provide informative NMR spectra indicated a radical cation, EPR results excluded free-radical species. Dynamic light scattering experiments, in comparison with model systems, revealed strong aggregation for the Carr–Price complex, rationalising the low stability, NMR problems and dimerisation observed by chemical quenching. The VIS data support structural similarity of the blue Carr–Price product with the delocalised anhydroretinylic cation, and a detailed structure of the antimony complex is evaluated.
5 citations
Journal Article•
TL;DR: In this paper, a quantitative determination of L-arginine with α-naphthol and 2,3-Butanedione in detail is described, and the best results could be achieved with the determination wavelength of 525 nm, color reaction temperature of 30 ℃, response time of 15 min and 15g/L NaOH.
Abstract: Objective To describe a method for the determination of L-arginine in fermentation broth.Methods This paper studied a quantitative determination of L-arginine with α-naphthol and 2,3-Butanedione in detail.Results The best results could be achieved with the determination wavelength of 525 nm,color reaction temperature of 30 ℃,response time of 15 min and 15g/L NaOH.This method had a good stability and reproducibility.Conclusion This method can be used for the quantitative determination of L-arginine in fermentation broth.
4 citations
01 Jan 2007
TL;DR: In this article, a Douglas colorimetric method was used for determining the pentosan in pre-extraction liquor from eucalyptus chips by using visible spectra of xylose,glucose,mannose,galactose and kraft lignin.
Abstract: (State Key Lab of Pulp and Paper Engineering,South China University of Technology,Guangzhou,Guangdong Province,510640) The fcasibility of determining the pentosan in pre-extraction liquor from eucalyptus chips by using Douglas colorimetric method was discussed in this paper.The visible spectrums of xylose,glucose,mannose,galactose and kraft lignin were compared under the same color reaction conditions.The results showed that the disturbance from hexoses and lignin can be eliminated when the pentosan is identified and determined by the maximal absorption at 553nm.This colorimetric method is suitable for determining the xylan in the pre-extraction liquor from eucalyptus chips. The determination conditions were optimized in the experiment.The dosage of color reaction reagent is 10:1(V reagent:Vsample)and the heating time ror color reaction is 10 min.
3 citations
TL;DR: The present procedure is useful for screening for MDMA and MDA in seized tablets and should be used to avoid nonspecific color development.
Abstract: We have previously reported basic data on the specificity of the color reaction of 3,4-methylenedioxymethamphetamine (MDMA) and related drugs with chromotropic acid (CTA) and sulfuric acid. In this communication, we report an extended line of experiments that optimized reaction conditions, and we describe the application of this method to screening for MDMA or 3,4-methylendioxyamphetamine (MDA) in seized tablets. The optimal concentration of CTA and optimal reaction time at room temperature were 1.0 mM and 30 min, respectively. Final concentrations of MDMA of less than 100 μM should be used to avoid nonspecific color development. The CTA-dependent color reaction was also studied using aqueous extracts from seized tablets containing MDMA or MDA. On the basis of our results, we conclude that the present procedure is useful for screening for MDMA and MDA in seized tablets.
Patent•
20 Sep 2007
TL;DR: In this article, an indicator composition for an aldehyde type sterilizing agent which properly suppresses color reaction in color reaction for detecting aldehydes, recognizes coloration and requires no oxidation inhibitor was provided.
Abstract: PROBLEM TO BE SOLVED: To provide an indicator composition for an aldehyde type sterilizing agent which properly suppresses color reaction in color reaction for detecting aldehydes, recognizes coloration and requires no oxidation inhibitor. SOLUTION: The indicator composition for the aldehyde type sterilizing agent contains an alkali metal polymyxin methanesulfonate. COPYRIGHT: (C)2007,JPO&INPIT
Journal Article•
TL;DR: In this paper, the molybdo-phosphorus blue-photometry was applied to the determination of 1,3- dihydroxyacetone(DHA) in acidic glycerol solution.
Abstract: The molybdo-phosphorus blue-photometry was applied to the determination of 1,3- dihydroxyacetone(DHA)in acidic glycerol solution.Based on a systematic study on the conditions of the color reaction,the amount of the color reagent(a mixed solution of molybdic acid and phosphoric acid)used was 2.0 mL per 50 mL of reaction solution,and the reaction mixture was heated for 15 rain in a water bath at 100℃.Beer's law was obeyed up to 0.60 g of DHA per liter of solution,corresponding to the linear regression equation Y=2.308 X—0.025 9(r=0.995 8).DHA itself acted as a reductant for the molybdo-phosphate in the color reaction.The presence of small amounts of GALD,GLYA,HYPA and etc in the sample solution showed no significant interferences to the determination of DHA.
Journal Article•
TL;DR: The calibration curve indicated that the absorptivity was linearly correlated with the concentration of 1,8-dihydroxy anthraquinone in the range of 0.002～0.016 mg/ml(r 0.9998).
Abstract: Objective To establish a method for the determination of total anthraquinones in health foodsMethod Color reaction (Borntragers reaction) occurs sensitively when anthraquinones meet alkalis, producing stable red or purple-red color The absorption value of the colored sample solution was measured at 525 nmResults The calibration curve indicated that the absorptivity was linearly correlated with the concentration of 1,8-dihydroxy anthraquinone in the range of 0002～0016 mg/ml(r 09998) The average recovery of 1,8-dihydroxy anthraquinone was 9983% and the RSD was 247% Conclusion The method is accurate, sensitive, quick and cost-effective and can be used to determine total anthraquinones in health foods
Patent•
10 Apr 2007
TL;DR: In this article, the color reaction component is first dissolved in solvent, namely vegetal oil C1-C8-alkyl ester, and to thus obtained solution a non-solvent is admixed at rapid stirring, said nonsolvent not dissolving or dissolving insignificantly colour reaction component and being taken in amount as to form supersaturated solution.
Abstract: FIELD: self-copy papers. ^ SUBSTANCE: group of inventions relate to use of microcapsules containing color reaction component. Color reaction component is first dissolved in solvent, namely vegetal oil C1-C8-alkyl ester, and to thus obtained solution a non-solvent is admixed at rapid stirring, said non-solvent not dissolving or dissolving insignificantly color reaction component and being taken in amount as to form supersaturated solution. The latter is directly emulsified in water phase at rapid stirring and, immediately after that, resulting emulsion is processed so that encapsulation takes place therein. Microcapsules obtained in this way are further described as well as their employment in color reaction paper. ^ EFFECT: improved writing quality and economic and environmental advantages. ^ 33 cl, 1 dwg, 4 ex
TL;DR: The significance of the dinitrobenzoic acids in the Mohler reaction for the estimation of benzoic and of mononitrobenzosic acids has been demonstrated by an approach by synthesis as discussed by the authors.
Abstract: The significance of the dinitrobenzoic acids in the Mohler reaction for the estimation of benzoic and of mononitrobenzoic acids has been demonstrated by an approach by synthesis. The colour reaction is given only by dinitrobenzoic acids with two nitro groups ortho or para to each other. Further support has been obtained for the hypothesis of Meisenheimer & Patzig that colour development from compounds of this type is due to the formation of quinonoid structures.
Patent•
30 Jan 2007
TL;DR: In this paper, a process for encapsulating a solution of color reactants of color-reaction systems present in an aqueous emulsion accomplished by means of conventional microencapsulation processes is described.
Abstract: A process is described for encapsulating a solution of color reactants of color-reaction systems present in an aqueous emulsion accomplished by means of conventional microencapsulation processes, in which the color reactant is first dissolved in a solvent and a non-dissolver, which may insignificantly dissolve the color reactant, is mixed into the resulting solution in an amount that establishes a supersaturated solution while mixing at high speed, the supersaturated solution is emulsified immediately in the aqueous phase while mixing at high speed, and immediately thereupon the encapsulation is performed A vegetable oil C1-C8 alkyl ester is used as the solvent This process has economic and technological advantages For example, it can be used to produce microcapsules that have an advantageous narrow monomodal particle distribution, which results in improved writing performance
Patent•
30 May 2007
TL;DR: In this paper, a low-density biochip with tetra methyl benzidine (TMB) as a color active marker was used to detect a color reaction of a biomolecule.
Abstract: The measuring device has a detection reaction guide unit (1) with one or multiple containers (2), a measuring unit (6), a test cassette (9) with a low density biochip (14) and solution of tetra methyl benzidine as a color active marker. The low density biochip is selected form mycotoxins, eicosanoid, lungs marker and anti immunoglobulin E-immunoglobulin E (anti-IgE-IgE) .The loading and rinsing of the test cassette with reaction and auxiliary solutions is realized by reaction guidance and by evaluation of the color reaction control-processor. Independent claims are also included for the following: (1) a test cassette (2) a method for the production and evaluation of photo-metric, pixel-oriented detected measurement results of a color reaction of a biomolecule to be detected on low density biochip in file formats.
Patent•
03 Jan 2007
TL;DR: In this paper, the color reaction partner is firstly dissolved in a solvent, and a nonsolvent that, at most, slightly dissolves the colour reaction partner was admixed with rapid mixing to the solution obtained in the aforementioned manner.
Abstract: not available for EP1539340Abstract of corresponding document: WO2004028681The invention relates to a method for encapsulating a solution, which consists of color reaction partners of color reaction systems while being provided in an aqueous emulsion, by using conventional microencapsulation methods According to the invention, the color reaction partner is firstly dissolved in a solvent, and a nonsolvent that, at most, slightly dissolves the color reaction partner is admixed with rapid mixing to the solution obtained in the aforementioned manner The nonsolvent is admixed in an amount that results in a supersaturated solution The supersaturated solution is immediately emulsified with rapid mixing in the aqueous phase, and the encapsulation is carried out immediately afterwards A vegetable oil C1-C8 alkyl ester is used in the solvent This method exhibits both economic and technological advantages while enabling the production of microcapsules having an advantageously tight monomodal particle distribution that leads to an improved print rate
Patent•
15 Feb 2007
TL;DR: In this paper, a detection agent is constituted by dissolving a hydrogen ion concentration indicator, such as methyl red of 0.02 wt.%; a buffer solution of 17.5 ml; and a homogeneous catalyst for hydrogenation for hydrogenating organic-phosphorus-based nerve gases, for example, complex salts in an easily evaporable organic solvent of methanol etc.
Abstract: PROBLEM TO BE SOLVED: To provide a detection agent for detecting organic-phosphorus-based nerve gases by color reaction. SOLUTION: The detection agent is constituted by dissolving a hydrogen ion concentration indicator, for example, methyl red of 0.02 wt.%; a buffer solution of 17.5 ml; a moisturizer, for example, polyhydric alcohol such as glycerine and ethylene glycol of 15 ml; and a homogeneous catalyst for hydrogenation for hydrogenating organic-phosphorus-based nerve gases, for example, complex salts in an easily evaporable organic solvent of methanol etc. in such a way that whole quantity may be of 100 ml to acquire a color solution, impregnating filter paper made of cellulose with the color solution, and vaporizing an organic solvent. Since organic-phosphorus-based nerve gases are decomposed to generate hydrogen fluorides, which are acid components, into color reaction with a hydrogen ion indicator, it is possible to eliminate the need for a thermal cracking furnace for pretreatment, simplify a detection apparatus, and make it compact. COPYRIGHT: (C)2007,JPO&INPIT