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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81 citations
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TL;DR: Hippuric acid dissolved in pyridine producesa red-orange color upon the addition of benzenesulfonyl chloride and follows the Beer-Lambert Law over a wide range of concentrations.
Abstract: Hippuric acid dissolved in pyridine producesa red-orange color upon the addition of benzenesulfonyl chloride. The color has a stable absorbance at 380 mµ. It is sensitive in microgram quantities of hippuric acid and follows the Beer-Lambert Law over a wide range of concentrations. The mechanism of the color reaction is described.
79 citations
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TL;DR: The inhibition of the indophenol reaction by amino acids has been found to be reversed by increased nitroprusside levels in assay mixtures, and attention must be given to the control of their effects on the color reaction.
78 citations
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77 citations
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TL;DR: Rapid and simple acid-base titration was accomplished using a novel microfluidic paper-based analytical device (μPAD), which was applicable to the titrations of nitric acid, sulfuric acid, acetic acid, and ammonia solutions and agreed well with those obtained by classic acid- base titration.
Abstract: Rapid and simple acid–base titration was accomplished using a novel microfluidic paper-based analytical device (μPAD). The μPAD was fabricated by wax printing and consisted of ten reservoirs for reaction and detection. The reaction reservoirs contained various amounts of a primary standard substance, potassium hydrogen phthalate (KHPth), whereas a constant amount of phenolphthalein was added to all the detection reservoirs. A sample solution containing NaOH was dropped onto the center of the μPAD and was allowed to spread to the reaction reservoirs where the KHPth neutralized it. When the amount of NaOH exceeded that of the KHPth in the reaction reservoirs, unneutralized hydroxide ion penetrated the detection reservoirs, resulting in a color reaction from the phenolphthalein. Therefore, the number of the detection reservoirs with no color change determined the concentration of the NaOH in the sample solution. The titration was completed within 1 min by visually determining the end point, which required ne...
73 citations