Dear Thabet

You got 56.088 mg/mL

Vol=40 mL

So, 56.088x40/40mL

You used 40 mL to dissolve 7.83 g sample extract

So the amount is 56.088x40 mg/7.83g of extract

If you convert this into per gram,

56.088*40/7.83 mg per g sample extract

=286.5mg/g extract

By the way, which plant did you use? It seems over estimated value.

and According to you equation, the value provided (56.088 mg/mL) seems strange.

For eg. if you have sample reading, 1.000, the concentration will be :

=(1.000+0.0006)/0.0398

=25.14 ppm

=25.14 ug/mL

Regards

Shiva Ram Bhandari

Dear Abdulelah Ahmed Thabet,

To convert from mg/L to mg/Kg do the following:

Material (mg/kg) = [conc of material (mg/L) X volume of sample (mL)] / [sample weight (kg) x 1000] , So you need to convert L to ml and Kg to g. Also please repeat the experiment 3 times and check  that you follow the same steps to ensure that your values of material used in the acceptable range compared to the literature. 

Best regards

Dear Abdulelah Ahmed Thabet,

content of phenolic compounds in the extracts were calculated by the following formula:

                                               C = c .v/m′

Where, C is the total content of phenolic compounds (mg/g), c is the concentration of gallic acid determined from the standard curve (mg/mL), v is the volume of the extract (mL), m′ is the weight of pure tissue (g).

Best regards

Dear Abdulelah Ahmed Thabet,

content of phenolic compounds in the extracts were calculated by the following formula as explained by Soolmaz Soleimani:

                                               C = c .v/m′

Now, c = 56.088 mg /mL

v= 300uL or 0.3 mL

m = 0.059 g ( 40 ml solution contained 7.83 g of extract, 1 mL contained 7.83/40, and 0.3 mL contained 7.83/40 x 0.3 = 0.059g)

C = 56.088 x 0.3/0.059

    = 285.19 mg of GAE/ g of dry plant extract

With Regards

Ajay Sharma

Dear all

Thank you so much for your help and also for your quick response.

It seems there are two ways to convert concentration from GAE mg/ml to mg/g of dry plant extract according to almost all answers ( C = c . v / m' ) and Dr. Sharma's answer but, this second is shown as a simplification of v / m' : 40 ml  / 7.83g to this 0.3 ml / 0.059 g which results are 5.1 and 5.08, respectively.

Final results are almost similar (286.5 and 285.19 mg GAE / g of dry plant extract).

Dr Andres Silva in calculation volume of crude extract (300µL ) not considered in calculation - v / m' : 40 ml  / 7.83g .