A Simple and Rapid Colorimetric Method for the Determination of Captafol in its Formulations and Agricultural Produce

A simple and rapid colorimetric method for the microdetermination of captafol, based on its reaction with potassium trithiocarbonate in dimethylsulphoxide (DMSO) has been developed. The bright yellow colour, which appears immediately on mixing the fungicide with the reagent, is stabie for atleast 2 h. It gives maximum absorbance at 440 nm and follows Beer's law upto 17.5 ng mL¹ of fungicide solution. The method is quite sensitive (ε, 7.20 x 10³L mol⁻¹ cm⁻¹); with 0.5 μg mL⁻¹ being the minimum detection limit. The method has been applied with success to both formulation analysis and residues in grains and apples. A photometric titration procedure for formulation analysis of the fungicide has also been developed.