| Popis: |
We constructed nano-metal oxide (tin oxide, cerium oxide, cobalt oxide, iron oxide, nickel oxide, gold oxide, and silver oxide) -modified carbon paste electrodes (CPEs) for detecting flavonols (kaempferol, myricetin, and quercetin) and flavones (luteolin and apigenin) using high-performance liquid chromatography with an electrochemical detector (HPLC-ECD). Flavonoids are more efficiently catalytically oxidized on a gold oxide-modified CPE than on a bare CPE. For direct current mode, with the current at a constant potential, and measurements with suitable experimental parameters, a linear concentration from 40 to 1600 ng mL–1 was found. The limits of quantification for flavonoids were below 0.5 ng. The developed method detected flavonoids in urine samples. Findings using HPLC-ECD and HPLC with an ultraviolet detector were comparable. |
