Topic
Color reaction
About: Color reaction is a research topic. Over the lifetime, 1194 publications have been published within this topic receiving 19579 citations.
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TL;DR: In this paper, the application of several dyestuffs for the detection of magnesium in strongly alkaline medium has been examined, and several methods for detecting magnesium in presence of other cations have been discussed.
Abstract: The application of several dyestuffs for the detection of magnesium in strongly alkaline medium has been examined. In all cases cobalt and nickel give the same test as magnesium and manganese in some. Methods for the sensitive detection of magnesium in presence of other cations have been discussed. Titan yellow is a very delicate reagent for magnesium and more specific than 1·2·5·8 oxyanthraquinone. The latter reacts also with beryllium, lanthanum and cadmium, whereas these elements do not form a colored compound with titan yellow. A mixture of titan yellow and magnesium chloride can be used as a reagent for hydroxyl ions; the sensitivity being dependent upon the magnesium concentration. The reaction can also be applied as a spot test on filter paper. Anilin yellow S (Kahlbaum) reacts very sensitively with lanthanum and copper in weakly acid medium (acetate buffer p H around 5,0).
8 citations
01 May 2021
TL;DR: In this article, a rapid and accurate method for the determination of available phosphorus in alkaline soil by molybdenum blue spectrophotometry was established, which is simple, sensitive and accurate.
Abstract: A rapid and accurate method for the determination of available phosphorus in alkaline soil by molybdenum blue spectrophotometry was established. The alkaline soil samples were extracted by Olsen method. The effects of absorption wavelength, amount of chromogenic agent, amount of reducing agent and colour reaction time on the determination results were investigated. The results showed that the optimal conditions were as follows: the maximum absorption wavelength was 700 nm, the amount of chromogenic agent was 1 mL, the amount of reducing agent was 1 mL, and the colour reaction time was 15 min. The linear range of phosphorus concentration was 0.3 μg/mL ~ 1.8 μg/mL, and the recoveries ranged from 88.67 % to 92.17 %. The method is simple, sensitive and accurate.
8 citations
8 citations
8 citations
TL;DR: Thioridazine hydrochloride is proposed as a new sensitive and selective reagent for the spectrophotometric determination of chromium as discussed by the authors, which forms a blue coloured radical cation with chromium(VI) instantaneously at room temperature in 1-4 mol l-1 orthophosphoric acid medium.
Abstract: Thioridazine hydrochloride is proposed as a new sensitive and selective reagent for the spectrophotometric determination of chromium. The reagent forms a blue coloured radical cation with chromium(VI) instantaneously at room temperature in 1–4 mol l–1 orthophosphoric acid medium. The blue species exhibits an absorption maximum at 640 nm with a molar absorption coefficient of 2.577 × 104 I mol–1 cm–1. A 27-fold molar excess of the reagent is necessary for the development of the maximum colour intensity. Beer's law is obeyed over the concentration range 0.05–2 ppm of chromium(VI) with an optimum concentration range of 0.2–1.6 ppm. The effects of acidity, time, temperature, order of addition of reagents, reagent concentration and the tolerance limit of the method towards various cations and anions usually associated with chromium are reported. The method has been used successfully for the determination of chromium in chromium steels.
8 citations