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METHOD FOR THE ESTIMATION OF TOTAL PHENOLIC CONTENT USING THE FOLIN-
C ASSAY
Page
3
of
5
bath at 80
0
C for 5min. Decent the supernant in to 100mL volumetric Flask
containing previous solution. Allow to cool the solution and make up to the
mark with methanol (Solution-A). Pipette out 2.0mL of Solution-A and transfer
it into 25mL volumetric flask Make up to the mark with methanol (Solution-B)
Further pipette out 1mL from Solution-B in to a 15mL test tubes and add 5 ml of
Folin-Ciocalteu’s phenol reagent followed by 4 mL of 7.5% Sodium Carbonate
solution. Close & Keep the test tubes in dark condition up to 1hour for colour
development. Take the absorbance at 765nm against Blank using UV-Visible
spectrophotometer.
•
Extract containing 15% Polyphenols:
Weigh accurately 150-200mg of
Sample extract in 50mL volumetric flask and add 25mL of methanol , Sonicate
for 10min and make up to the mark with Methanol(Solution-A) Pipette out
2.0mL of Solution-A and transfer it into 25mL volumetric flask. Make up to the
mark with methanol (Solution-B). Further pipette out 1mL from Solution-B in to
a 15mL test tubes and add 5 ml of Folin-Ciocalteu’s phenol reagent followed by
4 mL of 7.5% Sodium Carbonate solution. Keep the test tubes in dark condition
for 1hour for colour development. Take the absorbance at 765nm against Blank
using UV- visible spectrophotometer.
8.0
Calculation:
Total Phenolic content in Salacia Species is calculated by below mentioned
formula,
A
Sample
D
standard
% Purity of Standard
%Total phenolic content = ---------- x ----------- x
A
Standard
D
sample
Where:
A
Sample
=
Absorbance of sample at 765nm
A
Standard
=
Absorbance of standard at 765nm
D
sample
=
Dilution of sample in mg per mL
D
standard
=
Dilution of standard in mg per mL
9.0
Controls (Precaution):
•
Prepared Folin-Ciocalteu’s phenol reagent can be used for 15 days if it stored under
dark condition.
•
Sodium carbonate solution should be prepared freshly and used.