Related Experiment Videos
Evaluation of the antioxidant activity by flow injection analysis method with electrochemically generated ABTS
Damir Iveković1, Stjepan Milardović, Mario Roboz
1Laboratory of General and Inorganic Chemistry and Electroanalysis, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, HR-10000 Zagreb, Croatia. divekov@public.carnet.hr
The Analyst
|April 27, 2005
Summary
A new flow injection analysis method simplifies antioxidant activity testing by electrochemically generating ABTS radical cations. This rapid technique offers accurate antioxidant capacity evaluation for pure compounds and beverages.
Area of Science:
- Analytical Chemistry
- Electrochemistry
- Biochemistry
Background:
- The Trolox equivalent antioxidant capacity (TEAC) assay is a standard method for evaluating antioxidant activity.
- Traditional TEAC assays involve time-consuming chemical preparation of 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cations.
- A need exists for faster and more efficient methods for antioxidant capacity determination.
Purpose of the Study:
- To develop a simple, rapid, and efficient method for antioxidant activity evaluation.
- To adapt the TEAC assay to a flow injection analysis (FIA) system.
- To generate ABTS radical cations online via electrochemical oxidation within the FIA system.
Main Methods:
- Adaptation of the TEAC decolourisation assay to a flow injection analysis (FIA) system.
- On-line generation of ABTS radical cations using an electrochemical oxidation flow-through cell.
- Optimization of FIA parameters including flow rate, injection volume, and ABTS radical cation/carrier ratio.
Main Results:
- A linear calibration curve for Trolox was achieved in the range of 10-100 microM with a limit of detection of 1.6 microM.
- The method demonstrated good reproducibility (RSD 1.95%) and high sample throughput (32 samples/hour).
- Excellent correlation was observed between the developed method and the classic TEAC assay for both pure compounds (r(2)=0.996) and beverage samples (r(2)=0.957).
Conclusions:
- The developed FIA-based method provides a rapid and reliable approach for antioxidant activity evaluation.
- Electrochemical generation of ABTS radical cations significantly reduces analysis time compared to chemical methods.
- This method is suitable for routine analysis of antioxidant capacity in various samples, including beverages.