Polarographic determination of the fungicide thiram in relation to its environmental and toxicological analysis

Abstract

Thiram has been determined in soil, water, and food stuffs to assess its environmental relevance. A remarkably sensitive pulse polarographic method has been developed. The method is based on the reaction of thiram with copper(II) perchlorate in the presence of butylmethylimidazolium bromide (ionic liquid) in acetonitrile. The reaction product exhibits an analytically useful diffusion controlled peak at −116 mV (Vs SCE) and thiram has been determined in the linearity range 3.33 × 10⁻⁷ to 1.67 × 10⁻⁵molL⁻¹ with correlation coefficient 0.991. With a view to study the fate of thiram in soil and the extent of surface and ground water contamination, the soil-adsorption of the fungicide on three Indian soils of different soil characteristics has been studied by using a batch-equilibrium method. The ground ubiquity score for the fungicide has a value of less than 1.8 which classifies thiram as non-leaching pesticide.

Keywords:

• thiram
• copper(II) perchlorate
• pulse polarography
• residue/formulation analysis
• soil adsorption study