Estimation of carbohydrate by Nelsons’s Method II
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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 )
description
Molybdenum (Blue Complex). + Cu² +. + Cu +. + Cu +. + Cu² +. Gluconic acid. PMA. 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. Materials. - PowerPoint PPT Presentation
Transcript of Estimation of carbohydrate by Nelsons’s Method II
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( 30-70 μg/ml).
5. Colorimeter or spectrophotometer.
Glucose (ml) 0 0.25 0.5 0.75 1 1.5 2 2
Tube # Blank 1 2 3 4 5 6 unk.
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)
60
30
1545
510
202535
40
5055
8 min.
COOL PMA 2 2 2 2 2 2 2 2
Reagent (ml)Shake Well
2 min.
D. W. (ml) 4 4 4 4 4 4 4 4
Read the Optical Density at 630 nm
Results
0
0.2
0.4
0.6
0.8
1
1.2
0 0.2 0.4 0.6 0.8 1 1.2
Conc.
Ab
s.
Samar A. Damiati
