A study of the electrochemical behaviour of methomyl on a gold electrode in a neutral electrolyte

Abstract

A gold electrode was used for the qualitative and quantitative electrochemical determination of analytical methomyl in a neutral electrolyte (0.050 M NaHCO3) using cyclic linear sweep voltammetry. In the potential range from –800 mV vs. SCE to 1000 mV vs. SCE the analytical methomyl was quantitatively determined in the concentration range 4.0–16 mg L-1. In the potential range from ‑1300 mV vs. SCE to 1300 mV vs. SCE, methomyl was qualitatively determined by two anodic and four cathodic reactions. Cycling the potential in this range for 150 min caused the degradation of the molecule, which was confirmed by HPLC analysis. On the other hand, technical methomyl exhibited an inhibition of the gold electrode surface due to the impurities.

Keywords

• insecticide
• methomyl
• gold electrode
• cyclic voltammetry