Estimation of carbohydrate by Nelsons

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Estimation of carbohydrate by Nelsonss Method II

• Cupric ions are reduced by sugars to cuprous
  ions, which quantitatively reduce phosphomolybdic
  acid to a blue complex.

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Materials

• 1. Alkaline copper reagent.
• 2. Phosphomolybdic acid reagent.
• 3. Standard glucose solution containing 1mg/ml.
• 4. Glucose solution of unknown strength( 30-70
  µg/ml).
• 5. Colorimeter or spectrophotometer.

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Tube Blank 1 2
3 4 5 6
unk.
2 min.
8 min.
Glucose (ml) 0 0.25 0.5
0.75 1 1.5 2
2
D. W. (ml) 2 1.75
1.5 1.25 1 0.5
0 0
Alkaline Cu 2 2 2
2 2 2
2 2 Reagent (ml)
PMA 2 2 2
2 2 2
2 2 Reagent (ml)
COOL
Shake Well
D. W. (ml) 4 4 4
4 4 4
4 4
Read the Optical Density at 630 nm
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Results
Samar A. Damiati