LIBERAÇÃO CONTROLADA DE PARAQUAT EM PARTÍCULAS DE QUITOSANA.

Paraquat is an herbicide that has been widely used in pineapple, cotton, rice, banana, potato, coffee, sugarcane, among others, since the 1960s, as it is low cost, highly effective and not cumulative to the ground. However, from the 1980s onwards, several cases of poisoning related to this agrochemical were observed and the herbicide ended up becoming very well known for its high toxicity. Thus, aiming to reduce the exposure and avoid the toxic effects of this herbicide, the objective of this study was to promote the anchoring of Paraquat in polymeric chitosan nanoparticles and to evaluate the behavior for its controlled release. The anchoring potential and controlled release of paraquat from the biopolymer were evaluated using conductimetric titration with a standardized NaOH solution and spectroscopy in the UV-vis region. The results obtained showed the efficiency of chitosan nanoparticles in the controlled release process of the anchored herbicide. [ABSTRACT FROM AUTHOR]