Chemical Test Carbohydrate
The qualitative or quantitative technique which is implemented to detect the existence or to assess a chemical compound and or chemical group by using a reactant is a chemical test.Various tests exist to chemical test carbohydrate and once carbohydrate is detected, advanced tests could be carried out to categorize and distinguish it from other compounds. The Molisch Test, The Iodine/Potassium Iodide Test, Benedict’s Test, Barfoed’s Test, Seliwanoff’s Test and Bial’s Test are chemical test carbohydrate.
Named after Austrian botanist Hans Molisch, the Molisch’s Test is a sensitive chemical test carbohydrate. Sulfuric acid desiccates the carbohydrate which results in the formation of an aldehyde which is constricted with two phenol molecules that displays a purple or red colored compound. The sample is combined with a small amount of Molisch’s reagent, which is a-naphthol dissolved in ethanol, in a test tube. A small amount of concentrated sulfuric acid is gradually poured to the mixture along the wall of the test tube without mixing to generate a bottom layer.The appearance of a purple ring at the border between the acid and the test layers indicate a positive reaction.Carbohydrates and monosaccharides will display a rapid positive test result in chemical test carbohydrate although disaccharides and polysaccharides has a much slower reaction.
The Barfoed’s Test is a chemical test carbohydrate that detects the presence of monosaccharides.One ml of the sample solution must be added together with 3 ml of Barfoed’s reagent, an acetic acid solution and a solution of acetetate cupric. The solution must be heated for three minutes in a boiling water bath and the appearance of a reddish precipitate will give out a positive result for monosaccharides.
Discovered by the American chemist Stanley Rossiter Benedict,one of the chemical test carbohydrate utilized to detect the existence of reducing sugars is the Benedict’s test.
One ml of the sample solution should be placed in a test tube with a 2 ml solution of the Benedict’s reagent which contains sodium citrate and sodium carbonate mixed with a copper sulfate solution.Once the solution is heated in a boiling water bath for three minutes, a reddish precipitate should form within three minutes if it tests positive.
Primarily, researchers conduct chemical test carbohydrates to examine the different reactions of carbohydrates with the reagents to categorize and detect its compounds.