The Electrochemical Behavior and Determination of Quercetin in Choline Chloride/Urea Deep Eutectic Solvent Electrolyte Based on Abrasively Immobilized Multi-Wall Carbon Nanotubes Modified Electrode

A new electrochemical analysis method, using choline chloride/urea deep eutectic solvents electrolyte and MWNTs modified electrode system has been developed. The electrochemical behavior of quercetin was investigated in the mixed choline chloride/urea deep eutectic solvent electrolyte and acetate buffer solution supporting electrolyte. A pair of redox peak of quercetin was obtained by using cyclic voltammetry in the mixed supporting electrolyte with 0.407 V of E-pa and 0.386 V of E-pc. A differential pulse voltammeter method (DPV) for the determination of trace quercetin was proposed. A good linear relationship was obtained between the oxidation peak current and the concentration of quercetin within the range from 9.95 x 10(-7) mol . L-1 to 4.76 x 10(-5) mol . L-1, was obtained with the linear regression equation of i(pa) = 526.49-5 x 10(8) c (r=0.9991), and the detection limit reach of to 3.6 x 10(-8) mol . L-1. The proposed method was used to determine quercetin in practical samples with the RSD of 1.1 to 1.6% and the percentage recovery of 9.3 to 102.2%, and the result was agreed well that by HPLC.