EVALUATION OF AGROCHEMICALS IN SOIL OF CONVENTIONAL AND AGROECOLOGICAL AGRICULTURAL PRODUCTION SYSTEMS. At the Contestado Settlement, Lapa, PR, soil samples from agroecological and conventional environments were evaluated against the agrochemicals alachlor, atrazine, chlorpyrifos and trifluralin. For sampling, 3 depths were considered, 10points were selected, 5 in an agroecological and 5 in the conventional environment, with sampling frequency was at 2-month intervals. The samples were characterized according to textural, chemical and fertility parameters and the data were used in the chemometric study (PCA) demonstrating that the environments are different. The method of extraction, identification and quantification was validated at the trace level. The analytes were analyzed by GC-MS/MS, the recovery values were between 83 to 113%, RSD less than 14%, LD equal to 0.01; 0.0028; 0.004 and 002 μg kg-1, LQ equal to 0.04; 0.008; 0.011 and 0.05 μg kg-1, for alachlor, atrazine, chlorpyrifos and trifluralin, respectively. Chlorpyrifos was identified in the Conv3 and trifluralin in the Agro2 and 3 and Conv2 environments. Therefore, the application of pesticides in conventional environments can contaminate agroecological environments. The effect of rain/precipitation on the samples was evaluated by simulation and it was found that the physical-chemical properties of the compounds and the soil have an influence on their behavior in the soil profile.

Este artigo descreve a síntese e caracterização de diferentes híbridos orgânico/inorgânicos formados entre a polianilina e o óxido de titânio. O método de preparação é baseado no processo sol-gel, partindo do isopropóxido de titânio como precursor. Duas rotas sintéticas visando a obtenção dos híbridos foram utilizadas, baseadas na mistura da anilina no meio reacional antes ou após a formação do óxido. Diferentes quantidades de anilina foram utilizadas visando compreender este efeito nas características do material final formado. As amostras foram caracterizadas por análise térmica, difratometria de raios-X, espectroscopias Raman, UV-Vis em modo refletância difusa e IV-TF, além de voltametria cíclica. Os resultados indicaram que os diferentes procedimentos experimentais foram bem sucedidos na obtenção de híbridos formados por nanopartículas de TiO2 (estrutura anatase) e polianilina em sua forma condutora, sal esmeraldina. Não foram detectadas grandes diferenças entre as amostras obtidas através das duas rotas sintéticas utilizadas, exceto pela quantidade de polímero formada nos materiais.

This paper describes the synthesis and characterization of organic/inorganic hybrid materials formed from TiO2 nanoparticles and polyaniline (PANI). The preparation method is based on a sol-gel technique using titanium tetra-isopropoxide as oxide precursor, and two synthetic routes to the hybrids formation were employed, based on the addition of aniline after or before the sol formation. Different amounts of aniline were used to verify this effect on the characteristics of the formed materials. Samples were characterized by electronic spectroscopy, Raman spectroscopy, Fourier transformed infrared spectroscopy, thermal analysis, X-ray diffractometry and cyclic voltammetry. Results show that the different experimental routes are successful to produce hybrids formed by oxides nanoparticles and polyaniline in its conducting form, the emeraldine salt. There are no strong differences between the samples obtained by the two synthetic routes employed, except by the amount of polymer in the final material.