The determination of diquat residues in potato tubers

Abstract

Calderbank, Morgan and Yuen's method for the determination of residues of diquat has been modified. Five samples are hydrolysed simultaneously in a household autoclave with perchloric acid. Diquat is separated with Dowex 50W–X2, 200 to 400 mesh, and measured spectrophotometrically after reduction with hydroxostannate(II) solution. The modified procedure is more sensitive, requires smaller samples, and is considerably faster than the original procedure.