Showing papers on "Color reaction published in 1973"
Patent•
29 Jun 1973TL;DR: An improved reagent system for determining calcium by the orthocresolphthalein complexone color reaction is described in this article, which utilizes an alkaline buffer containing an aminoloweralkanol providing a pH of about 10.2 - 10.5.
Abstract: An improved reagent system for determining calcium by the orthocresolphthalein complexone color reaction. The reagent utilizes an alkaline buffer containing an aminoloweralkanol providing a pH of about 10.2 - 10.5. A method for using the reagent is also described. The composition is stable for extended periods.
24 citations
15 citations
TL;DR: In this paper, small amounts of organic compounds are trapped from gas chromatographic columns on short lengths of cooled glass porous layer open tubular capillaries containing either an inert support like Celite or an adsorbent such as alumina.
15 citations
TL;DR: In this paper, a spectrophotometric study of the interference of bromide in the ferric chloride reaction for cholesterol has been conducted and the interference has been shown to be primarily an enhancement of the color reaction and secondarily an additive color owing to a change in the spectrum of the reagent blank.
10 citations
TL;DR: Osmium(VIII) produces two coloured species with lambda(max) 680 nm (green) and 530 nm (red) with excess of 2-amino-8-naphthol-3,6-disulphonic acid in aqueous solution and conforms to Beer's law over a concentration range of 1.5-10 microg of osmium.
9 citations
TL;DR: In this article, two main coloring matters responsible for the observed colors were prepared separately and their chemical structures were determined as a Meisenheimer compound (I-2Na) and a bicyclic compound (II-Na), respectively, as shown in Chart 2 and 3.
Abstract: Color reaction of picric acid with acetone in an aqueous alkaline solution under the Janovsky conditions was investigated. Two main coloring matters responsible for the observed colors were prepared separately and their chemical structures were determined as a Meisenheimer compound (I-2Na) and a bicyclic compound (II-Na), respectively, as shown in Chart 2 and 3. The correlation between the coloring matters and their roles in the reaction were discussed by comparing the spectral behavior of them with the spectral changes of the reaction mixture.
7 citations
TL;DR: In this paper, the color reactions of cyclohexanone and acetophenone with 1, 3, 5-trinitrobenzene were investigated, and two main coloring matters, a Meisenheimer type compound, IV Na and a tricyclic type compound V Na, were isolated from the reaction mixture of cyclosanone.
Abstract: The color reactions of cyclohexanone, and acetophenone, with 1, 3, 5-trinitrobenzene were investigated. Two main coloring matters, a Meisenheimer type compound, IV Na and a tricyclic type compound, V Na, were isolated from the reaction mixture of cyclohexanone. In the case of the reaction of acetophenone with excessive 1, 3, 5-trinitrobenzene, the Meisenheimer type compound, VII Na, was the sole coloring matter. From a comparison of the absorption spectral behavior of them with the color reaction mixtures, mechanisms of the color reactions of cyclohexanone, and acetophenone, under the spot test procedure were elucidated.
4 citations
TL;DR: In this article, the CPB2.1%PV 2.6×10-3M (CPB1.1%) was used to achieve 1:1/3.
Abstract: タンタルは酸性で臭化セチルピリジニウム(CPB)存在においてピロカテコールバイオレットと青色錯体を生成し,吸収極大は605～610nmである.また見かけのモル吸光係数は数万の値を示す.CPBが存在しない場合にもやはり同じ条件で同様に呈色し,吸収極大波長は変化しないが,見かけのモル吸光係数は前者の約1/3である.発色の最適条件はCPB1.6×10-3Mにおいて1:1塩酸5～8 ml/25 ml,0.1%PV 2.0ml/25 mlで4・5～45μg/25mlの範囲でベールの法則をほぼ満足する. 呈色は少なくとも20時間は安定である.PVの添加量をさらに増加した場合,605～610nmの吸収はほとんど変化しないが,新たに440および540～550nmの二つの極大が現われ,前者はタンタルの濃度とかかわりなく一定である。後者はタンタルの濃度が増すにつれて増大するが比例性はわるい.この二つの吸収はタンタル-PV相互反応により生ずるある種の集合体に基因するメタクロマジー帯であろうと考えられる.
4 citations
TL;DR: Based on this reaction a sensitive spectrophotometric method for determination of micro amounts of tin(IV) has been developed and several complexing anions do not interfere and they have been used for masking some of the cations which interfere in the determination.
2 citations
TL;DR: In this article, the iodometric determination method (titration method) of hydrogen peroxide (H2O2) extracted with methanol was studied in previous papers, which was found to be excellent in reproducibility and simplicity, however, it is not suitable because the extract is colored frequently.
Abstract: The iodometric determination method (titration method) of hydrogen peroxide (H2O2) extracted with methanol was studied in previous papers. This method was found to be excellent in reproducibility and simplicity, however, it is not suitable because the extract is colored frequently. For the purpose of improvement of the method above-mentioned, H2O2 extracted with methanol was reacted with titanic sulfate, and the colored solution was determined colorimetrically. The color was stable for a week. The color reaction was not inhibited by the oxidizing agent such as potassium bromate or benzoyl peroxide, and not by phosphates and some amino acids added in noodle. The recovery was 97-102%. The range of determination was 2-200ppm of H2O2 in noodles. The presented method was more superior to the previous method in simplicity and precision.
1 citations
TL;DR: In this article, the color reaction of aromatic aldehyde with acenaphthene was investigated to clarify the mechanism of the coloration, and it was assumed that the colouration might be ascribed to 1-(5-acenaphthenyl) benzyl cation derivative.
Abstract: The color reaction of aromatic aldehyde with acenaphthene was investigated to clarify the mechanism of the coloration. When the colored solution of aldehyde with acenaphthene in concentrated sulfuric acid was treated with ice water, bis [1-(5-acenaphthenyl) benzyl] ether derivative was obtained, as a reaction product. It was assumed that the coloration might be ascribed to 1-(5-acenaphthenyl) benzyl cation derivative.
TL;DR: An improved method is described for the rapid estimation of 5-hydroxyindole-acetic acid in urine based on the separation by thin-layer chromatography and color reaction with the sensitive reagent, p -dimethylamino-cinnamaldehyde.
TL;DR: In this paper, the color change was especially marked with Protizinic acid, one of the phenothiazine derivatives, and reported this to the doctors, being worried about the unexpected phenomena.
Abstract: Patients treated with Protizinic acid, one of the phenothiazine derivatives, found that their urine turned blue when it was mixed with tap water and reported this to the doctors, being worried about the unexpected phenomena. The refore the cause of this phenomena was examined.The color reaction of such phenothiazines as Chlorpromazine HC1 (Cp), Dimetotiazine (Dm), Protizinic acid (Pt), Promethazine HCl (Pm) and Metiazinicacid (Mt) to alkaline and acid reagents, purified water and tap water was examined. The pH of discoloring point was also determined by adding NaOH to test solutions which had been previously colored by HClO4. It was found that Pt and Mt solutions turned blue when mixed with tap water but had no color change when mixed with purified water. This color change was especially marked with Pt. The color substance in the Pt-HClO4 solution was not extractable by ether.The difference between tap water and purified water in the color reaction may be attributable to residual content of chlorine and iron ions in the tap water.
TL;DR: In this paper, a color reaction involving modified acetic anhydride-sulphuric acid test giving characteristic colors and their sequence in different oils and fats was described.
Abstract: This article describes a color reaction involving modified acetic anhydride-sulphuric acid test giving characteristic colors and their sequence in different oils and fats