Of the extremely large number of methods proposed for the detection of reducing sugars there are very few which may be. Reducing sugar tests such as benedict s and fehlings test can be used to determine whether sugars are present in urine, which can be indicative of diabetes mellitus. Olorimetric tests for reducing sugars and polysaccha rides have been known for a considerable time. The solution, therefore, stays blue showing a negative result. Heating the reagent with the solution of reducing sugar produces a red precipitate. Benedict s test is used to test for simple carbohydrates. They will react with a blue liquid called benedict s solution to give a brick red color. If reducing sugars have been shown to be present, a heavier precipitate is often observed when the test for non reducing sugar is conducted. Reducing sugars under alkaline condition tautomerise and form enediols. Benedicts test for reducing sugar february 25, 2015 by dr hamza arshad 24 comments this test is for finding whether the sugar is reducible or non reducible. Glucose found to be present in urine is an indication of diabetes mellitus.
Some sugars can act as reducing agents and these sugars. Since it is a non reducing sugar, it wont react with benedict s reagent. Some disaccharides have exposed carbonyl groups and are also reducing sugars. The correlation between the absorbance a for a tested reducing sugar and its molar concentration c was evaluated using five compounds. It is both qualitative as well as quantitative test.
The extent of colour change can be used to qualitatively. A reducing sugar is any sugar that is capable of acting as a reducing agent because it has a. Benedicts solution, a reagent for measuring reducing. Benedict s solution can be used to test for the presence of glucose in urine. Some sugars such as glucose are called reducing sugars because they are capable of transferring hydrogens. The benedict s test identifies reducing sugars monosaccharides and some disaccharides, which have free ketone or aldehyde functional groups. Benedict s test for reducing sugars the benedict s test allows us to detect the presence of reducing sugars sugars with a free aldehyde or ketone group.
From the shefield laboratory of physiological chemistry, yale university. It was the most common test for diabetes and was the standard procedure for virtually all clinical laboratories. A reducing sugar is one that contains, or can form, an aldehyde or ketone and that can act as a reducing agent. A simple automated microplate method for determining reducing. This test is used for laboratory detection of different sugars as well as diabetes via urine test. Benedict s solution is the principle reagent in both tests. Benedict s test is most commonly used to test for the presence of glucose in urine. They can also be used in a qualitative manner, such as in a titration experiment, to determine the amount of reducing sugars in a solution. Benedict s solution, or one of the many variants that evolved over the years, was used as the reagent of choice for measuring sugar content for more than 50 years. Benedicts test principle, preparation, procedure and. The test for non reducing sugars is often conducted on a food sample which tested negative for reducing sugar.