Principle : Barfoed's test reaction is based on the reduction of cupric acetate by reducing monosaccharides and reducing disaccharides. Reduction of cupric acetate produces cuprous oxide which gives a brick red precipitate. Monosaccharides usually react in about 1-5 min and produce a red precipitate.Jul 16, 2018

How does the Barfoed’s test differ from the Benedict’s test?

The Barfoed's reagent is similar to Benedict's reagent except that the pH is lower (around 4.5), and heating time is reduced to two minutes. Benedict's test would determine if the sample is a reducing sugar, and Barfoed's test would determine if it is a monosaccharide or disaccharide.

What indicates a negative Barfoed’s test?

Barfoed's reagent, a mixture of ethanoic (acetic) acid and copper(II) acetate, is added to the test solution and boiled. If any reducing sugars are present a red precipitate of copper(II) oxide is formed. The reaction will be negative in the presence of disaccharide sugars as they are weaker reducing agents.

How do you perform a Barfoed test?

How to perform the test: One ml of a sample solution is placed in a test tube. Three ml of Barfoed's reagent (a solution of cupric acetate and acetic acid) is added. The solution is then heated in a boiling water bath for three minutes.

Can Barfoed test be used to detect sugar in urine?

Chloride ions interfere in this test, therefore, Barfoed's reagent cannot be used to detect the presence of glucose in urine.

What is the importance of Barfoed’s test?

Barfoed's test is a chemical test used to detect the presence of monosaccharides which detects reducing monosaccharides in the presence of disaccharides. This reaction can be used for disaccharides, but the reaction would be very slow.

What is the indication of a positive result for Barfoed’s test?

Positive Barfoed's test: development of brick red color ppt within 3-5 minutes. Negative Barfoed's test: absence of red color.

What factors affect Barfoed testing?

Barfoed's test is a chemical test used for detecting the presence of monosaccharides. It is based on the reduction of copper(II) acetate to copper(I) oxide (Cu2O), which forms a brick-red precipitate. (Disaccharides may also react, but the reaction is much slower.)