Spectrophotometric determination of the fungicides captan and folpet in their commercial formulationsAuthor(s): Sumita Sood
Captan and folpet react with thiophenol in the presence of triethylamine in acetonitrile to form a bis (phenyl) trithiocarbonatewhich reactswith 2, 4- dinitrophenyl hydrazine in the presence of hydrochloric acid to formcorresponding hydrazone. The latter is transformed into an intense red quinoidal ion immediately onmaking solution alkaline. This observation have beenmade the basis of a simple spectrophotometricmethod for the determination of above fungicides. The red colour is stable for at least 6 hrs and shows ëmax at 510 nm using either fungicide. The method has been successfully applied to the analysis of above fungicides in their commercial formulations samples.