Adsorptive Stripping Voltammetric Quercetin Determination in Pharmaceuticals and Urine Samples Using a Long Service-Life Array of Carbon Composite Microelectrodes

This article presents for the first time a new working electrode with a long service life- the bismuth-plated array of carbon composite microelectrodes for the simple, fast and sensitive determination of quercetin by adsorptive stripping voltammetry. The main experimental conditions were selected. The calibration graph was linear from 1 × 10^-9 to 2 × 10^-8 mol L^-1 with an accumulation time of 60 s. The detection limit was equal to 4.8 × 10^-10 mol L^-1. The relative standard deviation for 2 × 10^-8 mol L^-1 of quercetin was 4.4% (n = 7). Possible interference effects resulting from the presence of other organic and surface active compounds and interfering ions were studied. The developed procedure was successfully applied to determine quercetin in pharmaceutical preparations and the spiked urine samples.