Voltammetric determination of 2,4-dinitrophenol and 2,5-dinitrophenol using a poly-aspartic acid modified electrode1

摘要

In pH 5.0, 0.1 mol l~(-1) NaAc-HAc buffer solution, 2,4-dinitrophenol and 2,5-dinitrophenol exhibited sensitive and distinguishable voltammetric responses at the glassy carbon electrode modified with poly-aspartic acid. By measuring the reduction peak currents of nitro groups in different positions, dinitrophenol isomers have been determined simultaneously and quantitatively. The linear calibration ranges were 1.1 × 10 ~(-6)-6.0 × 10~(-4) mol l~(-1) for 2,4-dinitrophenol and 7.0 × 10~(-7)-6.0 × 10~(-4) mol l~(-1) for 2,5-dinitrophenol, with detection limits of 2.7 × 10~(-7) and 1.1 × 10~(-7) mol l-1 respectively. This method has been applied to the detection of dinitrophenols in simulation water sample, and the recovery was from 96.7 to 102.5%.