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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 ...
Carbohydrate NMR spectroscopy is the application of nuclear magnetic resonance (NMR) spectroscopy to structural and conformational analysis of carbohydrates.This method allows the scientists to elucidate structure of monosaccharides, oligosaccharides, polysaccharides, glycoconjugates and other carbohydrate derivatives from synthetic and natural sources.
Since its discovery in 1904 until the 1960s, the Wöhlk test has mainly been used to detect the reducing disaccharide lactose in urine in medical laboratories. Although there were already a number of wet-chemical detection methods to identify sugars, such as the Fehling or Benedict test , those analyses could only differentiate between reducing ...
Unlike Michelson–Morley type experiments, Hughes–Drever experiments test the isotropy of the interactions of matter itself, that is, of protons, neutrons, and electrons. The accuracy achieved makes this kind of experiment one of the most accurate confirmations of relativity (see also Tests of special relativity). [A 1] [A 2] [A 3] [A 4] [A ...
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 ...
The rapid furfural test is a chemical test used to distinguish between glucose and fructose. The rapid furfural test is similar to Molisch's test but uses concentrated hydrochloric acid instead of concentrated sulfuric acid and the solution is boiled. [1] Dilute sugar solution is added to ethanolic 1-naphthol and concentrated hydrochloric acid ...
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.
A bioassay is a biochemical test to estimate the potency of a sample compound. Usually this potency can only be measured relative to a standard compound. [3] [1] A typical bioassay involves a stimulus (ex. drugs) applied to a subject (ex. animals, tissues, plants). The corresponding response (ex. death) of the subject is thereby triggered and ...