What Is The Colorimetric Method Of The Phenol Sulfuric Acid Method

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The phenol-sulfuric acid method is a simple and rapid colorimetric method to determine total sugar in a sample. The method detects virtually all classes of carbohydrates, including mono-, di-, oligo-, and polysaccharides. It is one of the most versatile, relatively easy and cheap approaches for determination of carbohydrate concentrations is the colorimetric method based on reaction between hydrolysed carbohydrate solution and a colouring reagent that develops colour that is detectible in the visible range of the electromagnetic spectrum. Reagents used for colorimetric detection include phenol and concentrated sulphuric acid. The furfural is allowed to develop colour by reaction with phenol and its concentration is detected by visible light absorption. …show more content…

Pentoses (5-carbon compounds) are then dehydrated to furfural, and hexoses (6-carbon compounds) to hydroxymethyl furfural. The phenol-sulphuric method is used for the estimation of total sugars and DNS method for reducing sugars. Reducing sugars have an aldehyde group or carbonyl functional group, which can be reduced to -OH group by chemical reaction by addition of the DNS reagent. Some sugars like fructose/ sucrose which is commonly found in fruit juice are non-reducing sugars and hence do not reduce the above because of absence of an aldehyde group which is why the phenol sulphuric method is

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