Hi there;

I am measurin DPPH antioxidant activity by Trolox standard and need an urgent help if possible since I am so confused with the calc.

In extraction process; I mixed 5 gr of my sample with 100 ml methanol. From this solution I have pipetted 50uL-100uL-150uL-200uL to glass test tubes and completed the volume to 200 uL by methanol.

Then, I added 3,8 ml DPPH to each test tube and after waiting in dark measured the absorbance at 515 nm. At the same time I prepared a zero solution which contains only DPPH and measured the absorbance of this also. And I calculated the %inhibition of each sample concentrations. Then I plotted a curve with %inhibition of sample against uL of sample I used (%inhibition x ul sample). Then I calculated the slope of the curve . (lets say A)

In addition, I prepared trolox standard solutions (100-200-300-400-500 uM) and I performed the same assay with these trolox standard solutions. Again I calculated the %inhibition of each trolox concentrations against zero solution(DPPH). I plotted a curve with %inhibition against uM of trolox concentration (%inhibition x uMsample). I calculated the slope of the curve (lets say B)

At the end; I divided A to B ( A/B) and get the result as uMTE/ul sample .

But when I see in literature, other results are expressed in umolTE/g sample. So how can I convert my result (uMTE/ul sample) to those expressed ( umolTE/g sample)?

Many thanks for your responses in advance since I need a help,

Regards ,