Selective square wave voltammetric determination of (+)-catechin in commercial tea samples using beta-cyclodextrin modified carbon paste electrode

Abstract

Osteryoung square wave cathodic or anodic voltammetry has been used for the determination of (+)-catechin (CAT) at physiological pH in the presence of 0.05 mol · L−1 phosphate/borate buffer using beta-cylcodextrin modified carbon paste electrode. A linear range up to 70.0 µg · mL−1 CAT in cathodic voltammetry and up to 45.0 µg · mL−1 CAT in anodic voltammetry was achieved. The method gave reproducible and reliable results with 1.35 µg · mL−1 CAT as a detection limit with R.S.D. less than 2%. The proposed electrode was applied successfully for the determination of CAT in commercial tea samples with acceptable recovery range (98–102%). The extraction of CAT from commercial tea samples was rather simple, making it suitable for studies with a large number of commercial tea samples giving high accuracy of the proposed method.