AVALIA??O DA DISSIPA??O NO AMBIENTE DO RATICIDA BRODIFACUM FORMULADO COMO BLOCO PARAFINADO

摘要

In the chemical control of rodents in the São Paulo city – Brazil, mainly rats, paraffined blocks containing the active ingredient (a.i.) brodifacoum, are put in gutters being subject to the action of the bad weather that could cart alterations in a.i. and transfer to other environments. Aiming to verify those possibilities, experimental systems with paraffined blocks were mounted simulating the field conditions. Also 100 blocks were put at gutters monitored weekly. Three blocks were weekly collected, for 10 weeks, of the systems and of the gutters, and analyzed by high performance liquid chromatography. The obtained data were used for the evaluation of the dissipation of active ingredient. The results pointed the stability of the molecule under real application environmental conditions, because 100% of a.i. was recuperated after exposition of the block. Although, in the experimental systems, about 50% of the blocks unfastened from the fixation wire to the fifth week of exhibition and the recovery of a.i. decreased gradually along the 10 weeks of the study, reaching 50% of the initial concentration.