Carbohydrates are a very important component of Storage and structural materials in the plants. The carbohydrates are stored as free sugars and polysaccharides. The basic units of carbohydrates are Monosaccharides.
When hydrolyzing the carbohydrates, it gives monosaccharides, but when hydrolyzing monosaccharides it cannot be split into simpler sugars. The hydrolyzed product of Polysaccharide is estimating by the resultant monosaccharides.
Determination of Carbohydrate by Anthrone Method
To estimate the amount of carbohydrate present in the given sample by using the Anthrone method
Carbohydrates are dehydrated with concentrated H2SO4 to form “Furfural”, which condenses with anthrone to form a green color complex which can be measured by using colorimetrically at 620nm (or) by using a red filter. Anthrone reacts with dextrins, monosaccharides, disaccharides, polysaccharides, starch, gums, and glycosides. But they yields of color where is to form carbohydrate to carbohydrate.
- Anthrone reagent: Dissolve 200mg of anthrone reagent in 100ml of concentrated H2SO4.
- Standard Glucose solution: a) Stock standard: Weigh 100mg of Glucose and transfer it carefully into a 100ml withDistilled water. (100mg of Glucose in 100ml of Distilled water). b) Working standard: Dilute 10ml of stock standard solution in 100ml with distilled water in a volumetric flask.
To take 0.2 to 1ml of working standard solution of five different test tube and add water to bring the volume to 1ml in each test tube add 4ml of anthrone reagent and mix the contents as well and cover the test tube with bath for 10 min then cool the test tube to the room temperature and measure the optical density in a photoelectric colorimeter at 620nm (or) by using a red filter.
Simultaneously prepare a blank with 1ml of distilled water and 4ml of anthrone reagent. Construct a calibration curve on a graph paper, by plotting the glucose concentration (10 to 100mg) on x-axis and absorbance at 620nm on the y-axis. Compute the concentration of the sugar in the sample from the calibration curve. While calculating the sugar concentration in the unknown sample, the dilution factor has to be taken into account.
The amount of Glucose present in the given sample ______________mg/ml.
Few Other Protocols:
- Estimation of Proteins by Lowry method
- Colorimetric Analysis: BRADFORD PROTEIN ASSAY
- Color reactions of Amino acids
- Qualitative Analysis: Color Reactions of Lipids
- Qualitative Analysis of Carbohydrates