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I am looking for a simple way to distinguish between glucose and fructose samples. Currently, I am doing that by melting temperature method. Can anybody suggest me some easy way to do that?

jacob wick
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4 Answers4

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One of the simplest ways would be bromine-water test. Bromine water oxidizes glucose to gluconic acid, hence decolorize the solution. Being a mild oxidizing agent, Bromine water is not capable of oxidizing fructose (ketone).

pradeep pant
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Go for Seliwanoff's Test. It is based on the simple fact that when heated, ketose sugars are more rapidly dehydrated than aldoses. After acidic hydrolysis of both, we add a pinch of resorcinol(0.5%) and concentrated HCl(3N). Fructose reacts to give a deep red cherry colour whereas Glucose reacts slightly to produce a faint pink colour.

Buck Thorn
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user76878
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Taste tests also work. Fructose is about 2.3 times sweeter tasting than glucose, and the tongue is a very good sweet-sensor.

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(source: wikipedia)

Ben Welborn
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Go for Osazone test.... add phenylhetrazine +sodium acetate + acetic acid...if yellow precipitate appears within two minutes of boiling in waterbath (needle shape crystals)then the sample is Fructose.. if yellow precipitate appears between 5 to 10 minutes of boiling in waterbath (broom shaped crystals)its glucose.

Amod Bhat
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