Question

Principle of carbohydrate estimation by phenol sulphuric acid method

Answer 1

CARBOHYDRATE ESTIMATION USING PHENOL SULPHURIC ACID METHOD

   
This is general method of carbohydrate estimation. It is a modification to the anthrone method of carbohydrate estimations.

REAGENTS

   5% aqueous phenol
   
   Carbohydrate standard (glucose solution of about 20-200mg/ml)
   
   Concentrated sulphuric acid
   
   Unknown carbohydrate sample.

PROCEDURES

   A standard curves is prepared by dispensing varied volume of 50µg/ml solution of  standard glucose solution into labeled tubes. The varied volumes of each tube is then made up to 0.4ml by adding distilled water. 0.2ml of phenol is added to each tube. 1ml of concentrated  sulphuric acid is then carefully dispensed to each tube. The solution should be allowed to stand for 20min before taking the reading at 490nm. The unknown sample should also be treated in the same manner as the standards.