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An example of a positive Seliwanoff’s test. Seliwanoff’s test is a chemical test which distinguishes between aldose and ketose sugars. If the sugar contains a ketone group, it is a ketose. If a sugar contains an aldehyde group, it is an aldose. This test relies on the principle that, when heated, ketoses are more rapidly dehydrated than ...
Theodor Seliwanoff (or Seliwanow), born as Fedor Fedorovic Selivanov (October 8, 1859 in Gorodischtsche, Pensa–1938) was a chemist who invented the Seliwanoff's test in 1887 while working in Metchnikow University of Odesa in Odessa, Russian Empire.
It is an analytical reagent for the qualitative determination of ketoses (Seliwanoff's test). It is the starting material for the initiating explosive lead styphnate . [ 22 ]
For Salkowski test's procedure one needs a sample, that is to be tested for sterols, as well as chloroform and concentrated sulfuric acid that represent Salkowski's reagent. Usually the solution of chloroform and the sample is prepared first and later treated with concentrated sulfuric (VI) acid.
Molisch test (using α-napthol) indicating a positive result (see purple ring). Molisch's test is a sensitive chemical test, named after Austrian botanist Hans Molisch, for the presence of carbohydrates, based on the dehydration of the carbohydrate by sulfuric acid or hydrochloric acid to produce an aldehyde, which condenses with two molecules of a phenol (usually α-naphthol, though other ...
Nylander's test is a chemical test used for detecting the presence of reducing sugars. Glucose or fructose reduces bismuth oxynitrate to bismuth under alkaline conditions. When Nylander's reagent, which consists of bismuth nitrate, potassium sodium tartrate and potassium hydroxide, is added to a solution with reducing sugars, a black precipitate of metallic bismuth is formed.
In organic chemistry, Fehling's solution is a chemical reagent used to differentiate between water-soluble carbohydrate and ketone (>C=O) functional groups, and as a test for reducing sugars and non-reducing sugars, supplementary to the Tollens' reagent test. The test was developed by German chemist Hermann von Fehling in 1849. [1]
The reagent was originally generated in situ by reducing iron pentacarbonyl with sodium amalgam. [5] Modern synthesis use sodium naphthalene or sodium benzophenone ketyls as the reducants: [1] [6] Fe(CO) 5 + 2 Na → Na 2 [Fe(CO) 4] + CO. When a deficiency of sodium is used, the reduction affords deep yellow octacarbonyl diferrate: [1]