Determination of residues from the herbicide 2,4-dichloro-1-(4-nitrophenoxy)-benzene in rice and wheat by electron capture gas-liquid chromatography.

A residue method has been developed which is capable of determining not only 2,4-dichloro-1-(4-nitrophenoxy)-benzene but a majority of the known metabolites of this compound. The residues are reduced to a common amine intermediate which is further derivatized and quantitatively measured by electron capture gas-liquid chromatography. The method is sensitive to 0.01 ppm and is readily suited to routine use. The method has been used on rice and wheat samples.