title: Rapid, fully automated flow injection antioxidant capacity assay.
abstract: A flow injection method for antioxidant capacity assessment based on a low-cost laboratory-made analyzer is reported. A sample of 30 microL is injected in acetate buffer stream, pH 4.6, that converges with ABTS*(+) reagent stream. Detection is achieved by monitoring absorbance at 414 nm. The proposed method achieves a sample throughput of up to 120 samples h(-1), the detection limit being 1.3 microM trolox. Precision was better than 5% relative standard deviation (n = 4) and the linear range was 4-100 microM, expanded to 250 microM trolox utilizing concentration gradients formed along the injected sample bolus. Information on reaction kinetics is obtained through a single injection. The method was applied to pure compounds and wine and honey samples. Good correlation was found between antioxidant capacity assessed through the proposed method and phenolic content: r = 0.94 for red wines, r = 0.96 for white and rose wines, and r = 0.89 for honeys.
authors.affiliation: Chemistry Laboratory, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece.
authors.forename: Eleni P
authors.initials: EP
authors.lastname: Labrinea
authors.forename: Constantinos A
authors.initials: CA
authors.lastname: Georgiou
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D001322:Autoanalysis / Q000379:methods; D052160:Benzothiazoles; D017022:Flow Injection Analysis / Q000379:methods*; D006722:Honey / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D012680:Sensitivity and Specificity; D013451:Sulfonic Acids; D014920:Wine / Q000032:analysis
chemical_list: D000975:Antioxidants; D052160:Benzothiazoles; D007202:Indicators and Reagents; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid