Showing papers on "Color reaction published in 1968"
TL;DR: The chapter focuses on the later modifications for the determination of DNA especially in microorganisms and animal tissues and presents the modifications described by Burton, Croft and Lubran, and Giles and Myers.
Abstract: Publisher Summary This chapter discusses the determination of DNA concentration with diphenylaraine and describes several other color reactions for DNA. The reaction between deoxyribose and diphenylamine is probably the most frequently used color reaction for the determination of DNA. The chapter focuses on the later modifications for the determination of DNA especially in microorganisms and animal tissues and presents the modifications described by Burton, Croft and Lubran, and Giles and Myers. Croft and Lubran were measuring the DNA in saline washes of human stomachs. The material has a high content of sialic acid, which seriously interferes in several color reactions for DNA, including Button's modified diphenylamine reaction. Sialic acid reacts in this method to give a color with a maximum absorption at 550 mμ. Giles and Myers found that the blank readings could be reduced by omitting the sulfuric acid and adding the acetaldehyde to the individual tubes. They also obtained a worthwhile increase of sensitivity by increasing the concentration of diphenylamine and altering the relative volumes of sample and reagent. Giles and Myers encountered turbidities in their reaction mixtures due to impurities in DNA extracts from plant tissues.
1,326 citations
TL;DR: The proposed method correlates with the method of Abell et al., has a repeatability of 0.7%, a day-to-day variability of 2.8% and a reproducibility between laboratories of 1%.
148 citations
TL;DR: Procedures are described for precipitating with barium, the intermediates of the pentose phosphate cycle and some related compounds, and a new colour reaction for erythrose-4-phosphate is reported.
49 citations
TL;DR: In this paper, a band of material giving the 3β-hydroxy- Δ 5 steroid reaction with antimony trichloride staining reagent and previously named "U 2 " was purified by further thin-layer chromatography and identified as 16β -hydroxydehydroepiandrosterone.
45 citations
TL;DR: In this paper, two methods for the analysis of amino sugars are presented, and the main features of the mechanism of the color reaction are outlined, factors affecting the reproducibility of the Elson and Morgan analysis and the role of 2-methyl-pyrrole in the production of color are discussed.
26 citations
TL;DR: In this article, a modified procedure of the cysteine-carbazole reaction for the determination of fructose was described, and the color intensity ratio of fructose to glucose was about 240.
Abstract: A modified procedure of the cysteine-carbazole reaction for the determination of fructose is described. By incubating the components of the color reaction at 40°C for 1 hr, fructose is determined with good sensitivity (the millimolar absorbance value of 29.3) and specificity (the color intensity ratio of fructose to glucose is about 240). When the principle of the two-point determination is applied to this modified procedure (1 hr and 3 hr at 40°C), fructose as small an amount as 0.4μg in the presence of 250-fold excess of glucose can be determined with an error of about 10%.
19 citations
TL;DR: In this article, a simple procedure for the determination of ribonucleic acid-deoxyribon nucleic acid phosphate is described, and the final color is stable, a phenomenon made possible by masking the excess molybdate by a citrate-arsenite mixture.
8 citations
TL;DR: In this article, it was confirmed that turbid substances which remained in saccharified liquid after digestion of starch slurry with bacterial alpha-amylase and glucoamylases were insoluble starch particles and that these materials were formed during heat treatment of the slurry in liquefaction process.
Abstract: It was confirmed that turbid substances which remained in saccharified liquid after digestion of starch slurry with bacterial alpha-amylase and glucoamylase were insoluble starch particles and that these materials were formed during heat treatment of the slurry in liquefaction process.In iodine staining reaction, the suspension of these materials showed only a slightly dirty blue color; even after boiling of this suspension for 30 min at 135°C, this staining reaction was not complete and the maximum color intensity could be obtained after treatment with 1 n caustic soda solution.It is assumed from the iodine color reaction, that the main component of these materials was glucose polymer of straight chain, like that of amylose, and that this would be strongly associated with each other to form the compact molecule.The method for determination of these insoluble starch particles in the starch slurry was established and by this method the contents of these materials were determined in some types of starches.
8 citations
4 citations
TL;DR: The role of ammonium ion in the color reaction of aminopyrine has been investigated in this article, and it has been shown that ammonium ions are essential to the coloration of 4-aminoantipyrine.
Abstract: The mechanism of a new color reaction of aminopyrine has been studied. Aminopyrine gives orange red coloration by the reaction with phenol and potassium ferricyanide in ammonium acetate or ammonium chloride buffer. Colored substance of this reaction has been isolated and determined to be 4-(1', 4'-benzoquinone-4'-imino) antipyrine, which is the same as the reaction product obtained from 4-aminoantipyrine. But in the reaction of aminopyrine it has been found that presence of ammonium ion is essential to the coloration, contrary to the reaction of 4-aminoantipyrine, and in presence of excess aminopyrine intensity of color is proportional to the concentration of ammonium ion. Further investigation of the role of ammonium ion in the color reaction of aminopyrine supports the suggestion that in the first step ammonium ion and phenol are oxydatively condensed to produce 1, 4-benzoquinone imide type intermediate, which reacts with aminopyrine to produce 4-(1', 4'-benzoquinone-4'-imino) antipyrine as the consequence of transdimethylaminaton. On the basis of these experiments, a new colorimetric determination method of ammonia has been established.
3 citations
Patent•
05 Jun 1968
TL;DR: In this article, a method for detecting the presence of UREA in a buffer solution was proposed, 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.
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.
TL;DR: The chemical structures of the color reaction products (Ib and Ic) obtained from butyl and p-tolylurea with diacetyl monoxime and glucuronolactone in phosphoric acid were elucidated by their physical properties as discussed by the authors.
Abstract: The chemical structures of the color reaction products (Ib and Ic) obtained from butyl-and p-tolyl-urea with diacetyl monoxime and glucuronolactone in phosphoric acid were elucidated by their physical properties. Ib develops immediately a red color in phosphoric acid and is thought to be one of the main reaction product or one of the main reaction intermediate responsible for the color reaction. Ib gave two kinds of diacetate, and their structures were also established.
TL;DR: In this article, four reaction products produced in the color reaction of m-dinitrobenzene with potassium cyanide were separated by a chromatographic technique with alumina, and two of them were determined as 2-ethoxy-6-nitrobenzonitrile and 4, 6-diethoxy-2, 3-benzenedicarbonitrile respectively.
Abstract: Four reaction products produced in the color reaction of m-dinitrobenzene with potassium cyanide were separated by a chromatographic technique with alumina. Two of them were determined as 2-ethoxy-6-nitrobenzonitrile and 4, 6-diethoxy-2, 3-benzenedicarbonitrile respectively. Remaining two substances were the main parts of the coloring matters, and their structures were presented as 2, 3-dihydro-4-nitro-3-oxo-1H-indazole-7-carbonitrile or 2, 3-dihydro-6-nitro-3-oxo-1H-indazole-7-carbonitrile and 2, 3-dihydro-6-nitro-3-oxo-1H-indazole-5-carbonitrile respectively. The reaction mechanism was also discussed.
TL;DR: In this article, the authors discuss the effect of different types of poisons on the performance of the human body and the human brain, and propose a method to mitigate the effects of different kinds of poisons.
Abstract: 試薬としてキノンジクロルジイミドを用い, 各アミンとの呈色反応を試みた.脂肪族アミンでは, 一級および二級アミンは黄色を呈し, 三級アミンは呈色しない.芳香族アミンでは, 一級アミンは一般的に赤かっ色を呈し, 二級アミンは特徴的な緑色に呈色する.三級アミンは一部緑色を呈するものがあるが, ほかは呈色が非常に弱い.この芳香族二級アミンの呈色を定量に応用した.試料アミンと試薬のエタノール溶液にフタル酸水素カリウム緩衝液を加えて, 沸騰水中で15分間加熱し, 25分間常温に放置したのち, 689mμで吸光度を測定する.ベールの法則には, 1μg/5mlから10μg/5mlまたは20μg/5mlの範囲で従った.この呈色は芳香族一級および三級アミンのうち, パラ位が空位であり, オルトまたはメタ位に電子供与基を有するアニリン誘導体も同様の呈色をして妨害する.
TL;DR: The color reaction between iron(III) and 2,4-dihydroxybutyrophenone has been studied to determine the optimum conditions for the analytical use of this reagent as discussed by the authors.
Abstract: The colour reaction between iron(III) and 2,4-dihydroxybutyrophenone has been studied to determine the optimum conditions for the analytical use of this reagent. The strongest colour developed at pH 2·9 to 3·0, and the complex exhibits an absorption maximum at 470 m µ. The composition of the complex is 1 to 1, as indicated by mole-ratio studies. The absorbance of the solution at 470 m µ obeys Beer's Law in the iron(III) concentration range 1·0 to 56·0 p.p.m. and the sensitivity is 0·074 µg per ml of the iron(III) solutions. The reagent is fairly selective for iron.
TL;DR: In this article, a 0.1% increase in the number of users was reported. But, this increase was due to a small percentage of the users who reported negative experience.
Abstract: 酢酸基の分子内分布の異なるポリビニルアルコール(PVA)についてホウ酸の存在下でヨウ素呈色を調べた。均一系で塩酸を触媒とし, 酢酸とPVAからつくった均一再酢化PVAは約1%以下の希薄水溶液では呈色反応を起こさず, ホウ酸の存在下で青色に呈色した。一方, 普通のアルカリケン化で得た部分ケン化PVAは赤色反応を起こしたが, 約0.01%以下の希薄水溶液では呈色せず, ホウ酸の存在下では均一再酢化PVAと同じく青色を呈した。この青色反応は分子内の水酸基分布と関係があり,,分子内の水酸基分布が不均一なものほど高い呈色度であることが見い出された。
TL;DR: Salicylamide (I) reacts with dimethylp-phenylenediamine, and K3Fe (CN)6 in an alkaline medium (phosphate buffer : pH 8.0) to give green coloration (indophenol dye) as mentioned in this paper.
Abstract: Salicylamide (I) reacts with dimethyl-p-phenylenediamine, and K3Fe (CN)6 in an alkaline medium (phosphate buffer : pH 8.0) to give green coloration (indophenol dye). This chromogen produced is extractable with chloroform, the extract showing an absorption maximum at 650mμ.A new spectrophotometric method, based on this color reaction, has been established to the determination of (I) in pharmaceutical preparations.Influences of 47 compounds were examined. The interferences from acetaminophene, ethoxybenzamide, salicylate, phenylephrine hydrochloride, sulpyrine, ascorbic acid, etc. are eliminated by the extraction with chloroform in an acidic medium. The recommended procedure is as follows. Sample {containing 100mg of (I)} is taken in a separatory funnel. To it are added 10ml of water and 10ml of 0.1 N HCl, and it is extracted 4 times with 30ml portions of chloroform. The extracts are combined and evaporated on a water bath. The residue is dissolved in 50ml of ethanol, and is made up exactly to 100ml with water. A 10ml aliquot is taken into another 100ml volumetric flask, and is made up to 100ml with ethanol. Ten ml of this solution is taken into another 100ml volumetric flask and prepared in the similar way.A 2 ml aliquot is transfered into a 30ml glass-stop-pered test tube. Five milliliters of buffer solution (phosphate buffer : pH 8.0), 2ml of 0.05% dimethyl-p-phenylenediamine solution and 1 ml of 1% K3Fe(CN)6 solution are added. After 5 min., the solution is shaken with 10ml of chloroform. The separated chloroform layer is dried with 2 g of Na2SO4, and is filtered. The absorbance is measured at 650mμ (ET) against chloroform. At the same time the absorbance of standard solution (ES) is determined, and the amount of (I) is calculated by ET/ES.
TL;DR: Palladium and uranium react with 4,4-acetalidine-bis-(3-methyl isoxazolone-5) in acid medium to give yellow color having a visual limit of identification at 2 and 15μg per ml as mentioned in this paper.
Abstract: Palladium and uranium react with 4,4-acetalidine-bis-(3-methyl isoxazolone-5) in acid medium to give yellow color having a visual limit of identification at 2 and 15μg per ml. This color reaction provides the basis of a new method for colorimetric determination of palladium and uranium. Copper also gives yellow color but it cannot be determined with this color reaction because the color intensity is not stable. The maximum tolerable limit of various ions is reported.
TL;DR: In this paper, a simple spot test for mono-nitrobenzenes is described, based on the production of an orange-yellow to blue color when treated with phenylacetonitrile in alkaline dimethylformamide solution.
Abstract: A simple spot test for mono-nitrobenzenes is described. It is based on the production of an orange-yellow to blue color when mono-nitrobenzenes are treated with phenylacetonitrile in alkaline dimethylformamide solution. About 60 nitrobenzenes were tested by the present method, and the limits of identifications were tabulated. The reaction mechanisms were also studied.
TL;DR: In this article, a spectrophotometric study of the color reaction of sodium salt of 3 hydroxy-4-((-2-hydroxy-1-naphthyl)azo)-1naphthalene sulfonic acid (SDB) with gallium and Indium is described for the determination of micromaounts of gallium.
Abstract: Spectrophotometric study of the colour reaction of sodium salt of 3 hydroxy-4-((-2-hydroxy-1-naphthyl)azo)-1-naphthalene sulfonic acid (SDB) with gallium and Indium is described for the determination of micromaounts of gallium and indium. The absorbance curves of the complexes at pH 3.0 show λ max of SDB alone at 550 mμ while for ga-chelate λ max is 580 mμ and for In-chelate it is 570 mμ. The study was made at 590 mμ where the reagent absorbs very little. The optimum conditions for the microdetermination of gallium and indium using this reagent have been described and include the effect of pH on colour intensity of chelate, effect of excess of reagent, range of adherence to BEER'S law, sensitivity, molar absorption coefficient, rate of colour formation and stability of colour at room temperature. The effects of various diverse ions have also been studied and it was found that many ions do not interfere in the spectrophotometric determination of Gallium and Indium using SDB.