Estimation of carbohydrate by Nelsons’s Method II Cupric ions are reduced by sugars to cuprous ions, which quantitatively reduce phosphomolybdic acid to a blue complex. Gluconic acid + Cu + + Cu² + + Cu + + Cu² + PMA Molybdenum (Blue Complex)

Materials 1. Alkaline copper reagent. 2. Phosphomolybdic acid reagent. 3. Standard glucose solution containing 1mg/ml. 4. Glucose solution of unknown strength( μg/ml). 5. Colorimeter or spectrophotometer.

Glucose (ml) Tube # Blank unk. D. W. (ml) Alkaline Cu Reagent (ml) min. COOL PMA Reagent (ml) Shake Well 2 min. D. W. (ml) Read the Optical Density at 630 nm

Results Samar A. Damiati