None of them is right. The MW Of DPPH is 394 g/mol. Hence to make a 0.1 mM solution , you will need to dissolve 39.4 mg of DPPH in methanol/ethanol. A simple way to check is for 1 M in 1000 mL you need 394 g, for 1 mM you need 394 mg, so for 0.1 mM you would require 39.4 mg. However, I would suggest making a higher stock 10 mM and then dilute it before use.

Ok Sir, but most of the research paper mentioned that 0.1mM DPPH Slution prepared either using 22.2 mg in 1000 ml or 1.9 mg in 100 ml.

Can you cite those papers?

http://www.ijppsjournal.com/Vol4Suppl5/6153.pdf

http://www.ijpsdr.com/pdf/vol2-issue3/12.pdf

http://www.ijrap.net/admin/php/uploads/309_pdf.pdf

http://theglobaljournals.com/paripex/file.php?val=MTIyOQ==

To me this appears wrong. I will advise to refer papers indexed only in a reputed journal.

Cm = 0,00001 M (0,1mM)

V = 0,25L (I want 250 ml)

Mw = 394,32

ms = ??

ms = 0,00001 [mol/L] * 0,25 [L] * 394,32 [g/mol]

ms = 0,000985 [g]

in 1L

ms = 0,00001 [mol/L] * 1 [L] * 394,32 [g/mol]

ms = 0,0039432 [g]

Agreed with Rohitash jambwal

Yes, I also agree and I am also using the same way for making DPPH solution in my experiments

I agree with Jamwal.

can anyone tell me how to prepare 0.004% DPPH thank

correction a little bit of conversion by Andrzej Ochrem.

Cm of 0,1 mM = 0.0001 M (NOT 0.00001 M).

With all your calculation, so for 250 ml, ms = 0.009858 g = 9.858 mg.

for 1 L of volume, ms = 0.039432 g = 39.432 mg (same as the calculation by Rohitash Jamwal).

can anyone help me regarding the problem of unstability of DPPH solution

So is it right if I have to make 0.1mM of DPPH sol, then i have to add 39.4mg in 1000ml methanol? 

That's right. Just dissolve 39.4mg DPPH in 1000mL methanol for making a 0.1mM solution.

Of course, you are right Jamwal!

39.4 mg dpph in 1000 ml methanol

do we use 100% methanol in this case?

The purity of methanol doesn't care, you can even choose any other suitable solvent as long as it doesn't contain DPPH as impurity...

3.94mg for 0.1mM in 100ml.

Of course you are right Emma

3.94mg for 0.1mM in 100ml.

about 2 mg for 50 ml

or

4 mg for 100 ml

0.0039g /100 ml

Both are wrong answer............the right one is 0.0039432 g/100 ml

for making 100 ml DPPH (1mM), we use 3.94 mg ......

is it correct ?

It is correct@Irfan

thank you

THANKS

For dissolving of DPPH use HPLC grade methanol.

use almost the MW to prepare the normality you need !!, very simple

Is it compulsory to dissolve DPPH in methanol for ethanolic extract.? What concentration should be make to estimate anti-oxidant activity.

From my experience, weight 22 mg of solid DPPH in 50 mL of methanol( stock solution) and keep in under -20 for furthering uses. Thereafter, for preparing ( work solution) take 6 mL of stock solution and reach the volume to 100 mL in volumetric flask by ethanol and be careful the absorbance at 517 nm in range ( 0.100-0.900).

Irfan ali Sabir Please notice that the weight you used is for 0,1mM, so for 100 ml (1mM) you need 39,432mg.

How do you make 0.6 mM DPPH solution ?

39.4mg/1000ml

39.4mg per1000ml solvent not 100ml as we say molar means in one litre

0.1 mM millimolar

What is the concentration of methanol???

Pure Methnol more than 99%

Thanks

Please what is the content of standard solution of this procedure???

Actually, it is a stock solution of DPPH (0.1mM), since DPPH does not dissolve properly in water.

So ....The blank sol. is just distilled water ???

Molecular weight of DPPH is 394.32. so 394.32gm dissolved for 1L to obtain 1M solution. 39.432gm dissolved in 1L for 0.1M solution

Mol wt is 394.32 that means 394 g/L for 1M as above said. To get 0.1mM solution;

394.32/1000 (1M)× 1/1000 (to get mM concentration) × 0.1 (req. Conc)× 100 (req. Vol)

So, 3.94 mg of dpph has to be dissolve in 100 ML of methanol.

my friend

you can prepare 0.1M as a stock solution by add 39.4 gm/L then take 10ml from this concentration and add to 1L for final

concentration 0.1mM.

you just need to dissolve 3.94 mg DPPH in 100 mL of methanol to get 1x10-4 M or 0.1mM

1 M = 1000 mM

1 M of DPPH = 394.32 gram of DPPH in 1 liter of solution (make the volume up to 1-liter level after dissolving the DPPH in less volume of methanol).

1 mM of DPPH must contain 0.394 grams in a 1-liter solution.

0.1 mM DPPH must contain 0.0394 gram of DPPH in 1 liter of solution.

Now, you make the changes according to the required volume.

Both are wrong.394.32gm dissolved for 1L to obtain 1M solution.

Make a stock of 1mM by using 394 mg DPPH in lit of methanol or ethanol

0.394 g DPPH in liter or 100 ml ethanol?

Dissolve 3.94mg DPPH in 100mL methanol to making a 0.1mM solution.

0.1 mM DPPH= 0.0394 g/lit.

Or 3.94 mg/100 ml of ethanol/methanol.

0.395 mg of DPPH dissolve in 100 ml of ethanol/ methonal solution, it's gets. 0.1 mM DPPH solution

0.039 g of DPPH in 1 litre of methanol solution you get 0.1mM dpph solution

0.0394 g or 39.4 mg DPPH in liter methanol gives a 0.1mM solution