Publications Repository - Gdańsk University of Technology

This study demonstrates the potential of a commercially available derivatization instrument coupled with HPLC for separation and on-line determination of antioxidants detected with widely used screening reagents - DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) or FCR (Folin-Ciocalteu's phenol reagent ). As the result of optimization, key parameters of the analytical procedure, were established: concentrations of derivatization reagents 1.5 mmol/L and 2.1 mmol/L in methanol for DPPH and ABTS, respectively and 40 % (v/v) FCR solution in water; reactor temperatures 130 oC for ABTS and FCR and 50 oC in the case of DPPH. In order to validate these procedures, Trolox equivalent antioxidant capacities (TEAC) for standard antioxidants obtained by post-column derivatization (on-line) and typical batch colorimetric methods (off-line) were compared; the corresponding measurements were found to be strongly correlated (Pearson coefficient: 0.973, 0.922, 0.853 for DPPH, ABTS and FCR, respectively). The results obtained for standard antioxidants and real fruit sample - aronia extract, confirm the applicability of the proposed system to the on-line detection of antioxidants. Its great advantage compared to current routine methods is that it provides chromatographic profiles and corresponding fingerprints of antioxidants (including unknown ones) along with quantitative determination of antioxidative potential, both - total and exhibited by individual compounds.

Authors

• dr hab. inż. Barbara Kusznierewicz link open in new tab ,
• Anita Piasek link open in new tab ,
• prof. dr hab. inż. Agnieszka Bartoszek-Pączkowska link open in new tab ,
• prof. dr hab. inż. Jacek Namieśnik link open in new tab