Simultaneous determination of dopamine and cysteamine by flow injection with multiple pulse amperometric detection using a boron-doped diamond electrode

摘要

A flow injection analysis (FIA) system with multiple pulse amperometric (MPA) detection was proposed for the simultaneous determination of dopamine (DOP) and cysteamine (CYS) using a cathodically pre-treated boron-doped diamond electrode (CPT-BDD). The electrochemical behaviors of DOP and CYS were evaluated by cyclic voltammetry in a potential range from 0 to 1.7 V at a scan rate of 0.05 V s(-1) using 0.05 mol L-1 H2SO4 as supporting electrolyte. Two oxidation peaks were observed during anodic potential scanning, at potentials of 0.8 V (DOP) and 1.6 V (CYS). Under optimized experimental conditions, such as potentials E-1 = + 0.8 V 100 ms(-1) (pulse potential at which DOP was oxidized) and E-2 = + 1.6 V 200 ms(-1) (pulse potential at which both analytes were oxidized), the analytical curves were linear in the concentration ranges from 5.0 x 10(-7) to 1.3 x 10(-4) mol L-1 for DOP and from 5.0 x 10(-7) to 1.5 x 10(-4) mol for CYS, with detection limits of 1.1 x 10(-8) and 1.3 x 10(-8) mol L-1, respectively.