Linear Voltammetric Determination of Phoxim Using SWCNTs-nano Au-BMIMPF6 Modified GCE as Working Electrode

A mixture of dispersion of SWCNTs and nano Au solution was added dropwise onto the surface of glassy carbon electrode (GCE), after air-drying, methanol solution of ionic liquid, BMIMPF6 was added dropwise onto the surface of the above electrode. The modified electrode, designated as SWCNTs-nano Au-BMIMPF6/GCE was thus prepared. Electrochemical behavior of phoxim at the modified electrode was studied by cyclic voltammetry in a phosphate buffer supporting electrolyte of pH 4.0 in the potential range of -1.1 to -0.1 V (vs.SCE). As shown by the experimental results, a significant reduction peak was observed at -0.81 V, and linear relationship between values of reduction peak current and concentration of phoxim was kept in the range of 6.0×10-7 to 1.2×10-3mmol·L-1, with detection limit (3S/N) of 3.0 ×10-7mmol·L-1. Based on these findings, a method for determination of phoxim by linear voltammetry was proposed. Recovery was tested by standard addition method, giving values of recovery and RSD′s (n=6) in the ranges of 96.0%-105.5% and 3.3%-3.9% respectively.