To obtain the concentration of polyphenols I made a calibration curve of GA. The equation was y = 0,0351x + 0,0098. I solved 10 gram of green tea in 200 ml of water for 2h at 50°C. Afterwards I took 40 ml of this extract and diluted it to 200 ml to color the textile for 45 min. Every 15 min I took a sample of 5 ml to examine it in the uv vis and I used 1 ml of the 5 ml for the Folin Ciocalteu method. How do i get to mg GA/g dry tea ?
my absorbance for example was 0,14 and 0,124
What is the amount of the reagent used?
Is the standard compound amount one ml as the solutions to be measured?
Please give more information so that I can measure the concentrations.
best regards
Hi Louise Lambrecht
For the sample with absorbance value of 0.14, you can perform the following calculation procedure:
from the gallic acid standard equation we can write:
x= (0.14-0.0098)/0.0351=3.7094 mg GAE/L coloring solution
x= 3.7094 *10-3 mg/1ml coloring solution
= 3.7094 *10-3 *200 mg/200 ml coloring solution
= 741.88034 mg/200 ml coloring solution OR:
= 741.88034 mg/40 ml tea extract
= 741.88034*5 mg/200 ml tea extract
= 3709.4 mg/200 ml tea extract
= 3709.4 mg/10 g tea
= 370.94 mgGAE/g green tea
Best wishes
Duried
What is the amount of the reagent used?
Is the standard compound amount one ml as the solutions to be measured?
Please give more information so that I can measure the concentrations.
best regards
To help you calculate, can you clearly detail your method? You used which volume of extract, which volume of Ciocalteu folin and which volume of sodium carbonate.
I used 5 ml of Folin reagent and 2ml of Na2CO3 and 1ml of diluted tea extract from the wastewater
- Badges
- Science topic
- Similar topics
- Phytochemistry
- Extracts