I prepared Trolox working solution at different concentration - 0, 200, 500..800 uM in 10 ml abs MeOH. DPPH was used as antioxidant assay.
For antioxidant activity procedure, 0.15 ml of each Trolox working solution was added to 2.85 ml DPPH assay. Absorbance (515 nm) vs Trolox conc. gave linear correlation (R2=0.96776).
Working solution of sample was prepared by dissolving 20 mg dried sample in 10 ml abs MeOH, then 0.15 ml of it was mixed with 2.85 DPPH assay. Let say I got a certain absorbance value corresponding to 200 uM Trolox, how could I convert it to Trolox equivalent / (g-dry mass)? I confused whether to multiply the denominator with 10 ml or 0.15 ml. Thank you.