Benedict's reagent (also called Benedict's solution or Benedict's test) is a chemical reagent named after an American chemist, Stanley Rossiter Benedict.^[1] A reactant or reagent is a substance consumed during a chemical reaction. ... Stanley Rossiter Benedict (1884 – 1936) is an American chemist best known for discovering Benedicts reagent, a solution that detects certain sugars. ...

Benedict's reagent is used as a test for the presence of all monosaccharides, and generally also reducing sugars. These include glucose, galactose, mannose, lactose and maltose. Even more generally, Benedict's test will detect the presence of aldehydes (except aromatic ones), and alpha-hydroxy-ketones, including those that occur in certain ketoses. Thus, although the ketose fructose is not strictly a reducing sugar, it is an alpha-hydroxy-ketone, and gives a positive test because it is converted to the aldoses glucose and mannose by the base in the reagent.^[2]. Monosaccharides are the simplest form of carbohydrates. ... A reducing sugar is any sugar that, in basic solution, forms some aldehyde or ketone. ... Glucose (Glc), a monosaccharide (or simple sugar), is an important carbohydrate in biology. ... Galactose (also called brain sugar) is a type of sugar found in dairy products, in sugar beets and other gums and mucilages. ... D and L forms Haworth projection of mannose in its α-D-mannopyranose form. ... Lactose is a disaccharide that consists of β-D-galactose and β-D-glucose molecules bonded through a β1-4 glycosidic linkage. ... Maltose, or malt sugar, is a disaccharide formed from two units of glucose joined with an α(1→4) linkage. ... An aldehyde. ... Fructose (or levulose) is a simple sugar (monosaccharide) found in many foods and is one of the three most important blood sugars along with glucose and galactose. ... Glucose (Glc), a monosaccharide (or simple sugar), is an important carbohydrate in biology. ... D and L forms Haworth projection of mannose in its α-D-mannopyranose form. ...

Benedict's reagent can be prepared from sodium carbonate, sodium citrate and copper(II) sulfate.^[3] It is often used in place of Fehling's solution. Sodium carbonate (also known as washing soda or soda ash), Na2CO3, is a sodium salt of carbonic acid. ... Sodium citrate is the sodium salt of citric acid with the chemical formula of Na3C6H5O7. ... Flash point non flammable Related Compounds Other cations Nickel(II) sulfate Zinc sulfate Except where noted otherwise, data are given for materials in their standard state (at 25 Â°C, 100 kPa) Infobox disclaimer and references Copper(II) sulfate (sulphate in most Commonwealth nations) is the chemical compound with the formula... Fehlings solution is a solution used to differentiate between water soluble aldehyde and ketone functional groups, although ketose monosaccharides (such as fructose) will also test positive, due to conversion to aldoses by the base in the reagent [1]. For this reason, Fehlings reagent is sometimes referred to as...

Benedict's reagent contains blue copper(II) ions (Cu²⁺) which are reduced to copper(I) (Cu⁺). These are precipitated as red copper(I) oxide which is insoluble in water. Precipitation is the condensation of a solid from a solution during a chemical reaction. ... Copper(I) Oxide or Cuprous oxide (Cu2O) is an oxide of copper. ...

Chemical test

To test for the presence of monosaccharides and reducing disaccharide sugars in food, the food sample is dissolved in water, and a small amount of Benedict's reagent is added. The mixture is heated in a boiling water bath, and any precipitate formed is recorded as a positive result for the presence of reducing sugars in the food.

The common disacharrides lactose and maltose are directly detected by Benedict's reagent, because each contains a glucose with a free reducing aldehyde moiety, after isomerization.

Sucrose (table sugar) contains two sugars (fructose and glucose) joined with by their glycosidic bond in such a way as to prevent the glucose isomerizing to aldehyde, or the fructose to alpha-hydroxy-ketone form. Sucrose is thus a non-reducing sugar which does not react with Benedict's reagent. Sucrose indirectly produces a positive result with Benedict's reagent if heated with dilute hydrochloric acid prior to the test, although after this treatment it is no longer sucrose. The acidic conditions and heat break the glycosidic bond in sucrose through hydrolysis. The products of sucrose decomposition are glucose and fructose, both of which can be detected by Benedict's reagent, as described above. Flash point N/A Except where noted otherwise, data are given for materials in their standard state (at 25 Â°C, 100 kPa) Infobox disclaimer and references Sucrose (common name: table sugar, also called saccharose) is a disaccharide (glucose + fructose) with the molecular formula C12H22O11. ... This article is about sugar as food and as an important and widely-traded commodity. ... In chemistry, a glycosidic bond is a certain type of functional group that joins a carbohydrate (sugar) molecule to an alcohol, which may be another carbohydrate. ... In chemistry, a glycosidic bond is a certain type of functional group that joins a carbohydrate (sugar) molecule to an alcohol, which may be another carbohydrate. ... Hydrolysis is a chemical reaction or process in which a chemical compound is broken down by reaction with water. ...

Starches do not react or react very poorly with Benedict's reagent, due to the relatively small number of reducing sugar moieties, which occur only at the ends of carbohydrate chains. Inositol (myo-inositol) is another carbohydrate which produces a negative test. Starch (CAS# 9005-25-8, chemical formula (C6H10O5)n,[1]) is a mixture of amylose and amylopectin (usually in 20:80 or 30:70 ratios). ... Inositol, (of which the most prominent naturally-occurring form is myo-inositol, cis-1,2,3,5-trans-4,6-cyclohexanehexol), is a carbocyclic polyol that plays an important role as the structural basis for a number of secondary messengers in eukaryotic cells, including inositol phosphates, phosphatidylinositol (PI) and phosphatidylinositol...

Benedict's reagent can be used to test for the presence of glucose in urine. Glucose found to be present in urine is an indication of diabetes type 2. Once a reducing sugar is detected in urine, further tests have to be undergone in order to ascertain which sugar is present. Only glucose is indicative of diabetes. This article is about the urine of animals generally. ... This article is about the disease that features high blood sugar. ...

Quantitative reagent

Benedict's quantitative reagent is used to determine how much reducing sugar is present. This solution forms as white precipitate rather than a red one and so can be used in a titration. The titration should be repeated with 1% glucose solution instead of the sample for calibration. A scale for measuring mass A quantitative property is one that exists in a range of magnitudes, and can therefore be measured. ... This article is about volumetric titration. ... calibration refers to the process of determining the relation between the output (or response) of a measuring instrument and the value of the input quantity or attribute, a measurement standard. ...

References

1. ^ Benedict, S. R. (1908). "A Reagent For the Detection of Reducing Sugars". J. Biol. Chem. 5: 485–487. 
2. ^ http://www.uni-regensburg.de/Fakultaeten/nat_Fak_IV/Organische_Chemie/Didaktik/Keusch/D-Fehling-e.htm
3. ^ Robert D. Simoni, Robert L. Hill, and Martha Vaughan (2002). "Benedict's Solution, a Reagent for Measuring Reducing Sugars: the Clinical Chemistry of Stanley R. Benedict". J. Biol. Chem. 277 (16): 10-11.