HPLC and GC/MS of Metribuzin and Its Degradation Products from Alginate-Linseed Oil Controlled Release Formulations

Abstract

In the preparation of alginate-clay-linseed oil controlled release formulations of metribuzin and the evaluation of their release rates, degradation of the metribuzin was observed. The degradation products were separated by HPLC and identified by GC/MS as diketometribuzin (DK), deaminated metribuzin (DA), and deaminated diketometribuzin (DADK). The HPLC method developed afforded baseline separation without the use of acid or buffers in the mobile phase. These same products are the major metabolites of metribuzin in plants and soil. The production of DK was directly proportional to the amount of linseed oil in the formulation whereas DA appears to be inversely proportional to linseed oil concentration.