I have got following answer but bit confused
The total phenolic contents in all samples was calculated the using the formula:
C = c V/m
where, C = total phenolic content mg GAE/g dry extract, c = concentration of gallic acid obtained from calibration curve in mg/mL, V = volume of extract in ml, m = mass of extract in gram.
we have used following procedure
- 500 μl of the sample was taken in 25 ml volumetric flask. To this, 10 ml of water and 1.5 ml of Folin ciocalteu reagent were added.
The above mixture was kept for 5 min. and then 4 ml of 20 %sodium carbonate solution was added and the volume was made up to 25 ml with distilled water.
The mixture was kept for 30 min. and the absorbance of the blue color developed was recorded at 765nm. than graph ploted and we got y=mx+c, from that we got C now
wt of crude drug = 50 g
wt of dried extract = 100 mg
sample is dissolved in 100ml methanol
sample used for assay is 0.5ml
so my question is what is V in our case and what is m in our case.
some time i also find to C = c V DF/m where DF is dilution factor so what is it in our case
First, you have to determine the slope of the calibration curve (using different concentrations of Gallic Acid as function of their absorbances). Then you divide the absorbance of your extract by the slope in order to obtain the concentration in mg/ml.
In a second time, and in order to obtain the concentration in mg GAE/g DM (dry matter), you multiply the concentration obtained above (in mg/ml) by "a", and you divide the result by "b" and by "c", where "a" is the volume of solvent (water or else), "b" is the mass of solid matrix extracted and and "c" is the percentage of dry matter of the matrix.
Vaibhavi Savalia
The total phenolic contents in all samples was calculated the using the formula: C = c V/m where, C = total phenolic content mg GAE/g dry extract, c = concentration of gallic acid obtained from calibration curve in mg/mL, V = volume of extract in ml, m = mass of extract in gram.
At first, prepare a various concentration of Gallic acid as a general absorbance. Then, do fraction or divide the extract for obtaining its concentration in mg/ml. Take look to the following papers.
https://aip.scitation.org/doi/pdf/10.1063/5.0002657
https://doi.org/10.3390/antiox10111656
https://doi.org/10.3389/fpls.2021.631421
Good luck.
Use equation of your Graph ..for simplicity what was your x axis and y axis
Depends entirely on your final expression of result. If it is mg GAE/g dry extract then m* = g of dried extract; v* = mL of extracting medium while if the expression is mg GAE/g crude drug, then m* = g of crude drug; v* = mL of extracting medium.
Regarding DF: It is related to several factors (working protocol, instrumental range, concentration of working sample). E.g. if your final sample (for which you want to know the absorbance at respective wavelength) is too much concentrated, then you might need to dilute the sample (lets say 10 times). After taking the absorbance, during calculation just multiply the results with 10 (DF).
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