Determination of Thiophanate Methyl in its Formulation and Agricultural Produce by Differential Pulse Polarography

A differential pulse polarographic (DPP) method for the determination of thiophanate-methyl, a widely used fungicide, has been developed. The measurements at dropping mercury electrode (DME) were made in aqueous sulphuric acid (pH 2–3) in the presence of potassium perchlorate as supporting electrolyte. A well-defined diffusion controlled anodic wave at a peak potential of -0.1 V vs saturated calomel electrode (SCE) was obtained. The relationship between peak current and fungicide concentration was linear up to 13.68 µg ml−1. The method has been applied to both formulation and residues analysis in foodstuffs. The recovery was in the range 98.8–99.2% in formulation analysis and 90.5–98.0% in residue analysis with a maximum relative standard deviation of ±1%.