Hi Mithun,
I used sigma DPPH (mw 394.32) and prepared 0.1mM in methanol. Abs gives above .5 @517nm.
I also used Sigma Aldrich. Acording to original method proposed by Brand-Williams et al. a 0.06 microM methanolic solution of DPPH should give the absorbance of about 0.5 at 517 nm
Good luck
Thank you sir, but i need to know what may be the reason for low absorbance?
Try to prepare a 0.06 microM methanolic solution of DPPH (molecular weight 394.32) and check what the absorbance will be
May be the Himedia chemical is not so good.I always use DPPH from Sigma Aldrich.
Good morning Sir,
It is very low, it must be checked the status of your spectrophotometer
Best regards
Hi Mithun,
I'm unsure of the purity and expiry date of Himedia DPPH reagent which you have used for the experiments. Try not using highly aged DPPH reagent. The concentration which you have used is fairly good and widely reported. Try scanning the DPPH solution over 300 - 600 nm and check for the wavelength maxima, in case you are using aged DPPH reagent.
- Badges
- Science topic
- Similar topics
- Analytical Chemistry
- Extraction