In fact if you read the literature, you would find that many a time Trolox is one of the standard used in DPPH assay.

Thank you Jai Ghosh. Actually I saw two papers that used Trolox as a standard, but their raw materials were very different from mine. So I could not sure.

That is research.......unless you try you will never be sure.

Dear Kantar,

Yes, you can use Trolox instead of ascorbic acid. May you follow the following analytical procedure.

Analysis of DPPH

Reagents:0.1mMDPPH (weigh 0.0039g of DPPH into 100mL flask and fill up to mark)

100% methanol

1. standard: trolox make stock of 1000mg/L by measuring 10mg trolox into 10ml 100% methanol

2. then: prepare 0.1, 0.2, 0.4, 0.8, standards by taking 100µL , 200, 400 and 800 µL from stock to each standard, respectively and add 900 µL, 800 µL, 600 µL, 200 µL of 90%methanol.

3. prepare 0.01,0.02,0.04,0.08 by taking 100 µL of 0.1, 0.2,0.4,0.8 standard, respectively + 900µL of methanol and use 0.1 standard as fifth.

From the above, you will get your first result in mg/L using the linear equation which has generated from a series of working standards. To convert into mg/g, divide the previous result by your sample weight on dry matter basis which will give you the final result in mg/g(db). I hope it is clear.

Good Luck with your analysis!

Thank you very much Dear Abera.

Trolox can replace ascorbic acid in many cases but not everytime.

Yes, because in ABTS method, Trolox is Antioxidant control. And an analogue of hydrophilic vitamin E. And as a standard.

Trolox can be used in both DPPH and ABTS antioxidant assays.

Dear all,

I had a follow up question to Naciye's question on using Trolox as a standard free radical scavenging agent. My problem is; on ways of reporting the final result. Do we express our result in terms of the concentration of antioxidant present in our sample extract or in terms of percentage of inhibition or percentage free radical scavenging activity of the antioxidant compounds present in our sample extract?

Thanks,

Tilahun

Yes, Trolox can be used for DPPH assay.

Best regards!

please anyone can tell me reference value (Abs 515nm value ) for known concentration of trolox?

Grazie

Elena