SIMULTANEOUS DETERMINATION OF ATRAZINE AND DIURON IN PESTICIDE FORMULATIONS, IN SOILS AND WATERS AT PPB LEVELS BY DERIVATIVE SPECTROPHOTOMETRY

Binary mixtures of atrazine and diuron can be resolved by using derivative spectrophotometry. The procedure does not require any separation step and the method is suitable for samples containing 1-15 mug.mL-1 of atrazine and 1-10 mug.mL-1 of diuron. The mixture was determined in pesticide formulations and soils with good results. A solid-phase extraction has been combined with first derivative spectrophotometry to separate, recover and quantify both pesticides in groundwater samples at ppb levels. The recoveries are between 85-103% for atrazine and 94-106% for diuron.