Which is right for 0.1mM DPPH Slution preparation:
1: 22.2 mg in 1000 ml.
or
2: 1.9 mg in 100 ml
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.
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]
Yes, I also agree and I am also using the same way for making DPPH solution in my experiments
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.
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...
Both are wrong answer............the right one is 0.0039432 g/100 ml
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.
39.4mg per1000ml solvent not 100ml as we say molar means in one litre
0.1 mM millimolar
Actually, it is a stock solution of DPPH (0.1mM), since DPPH does not dissolve properly in 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.
Make a stock of 1mM by using 394 mg DPPH in lit of methanol or ethanol
Dissolve 3.94mg DPPH in 100mL methanol to making a 0.1mM solution.
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
- Badges
- Science topic
- Similar topics
- Phytochemistry
- Extracts