DETERMINATION OF TRACE XANTHINE BY ANODIC STRIPPING VOLTAMMETRY WITH CARBON NANOTUBE MODIFIED GLASSY CARBON ELECTRODE

Abstract

ABSTRACT The electrochemistry of xanthine (Xa) was studied by CV at a glassy carbon electrode modified with carbon nanotubes. A well defined, sensitive oxidation wave of xanthine and a small reduction wave were obtained. Based on the oxidation peak, a method for determination of xanthine with semi-derivative anodic stripping voltammetry at a glassy carbon electrode modified with carbon nanotubes was investigated. The stripping peak current is proportional to the concentration of Xa over the range 2.0 × 10−7–2.0 × 10−5 M with 1-min accumulation. The detection limit is 4.0 × 10−9 mol/L with 3-min accumulation. The method has been successfully applied to the determination of xanthine in human serum.