The miniaturized extraction techniques use less aggressive methods to the environment, since they generate less waste and spend a minimum of organic solvents, besides having a good selectivity and specificity in the extractions. In this context, liquid-liquid dispersive microextraction (DLLME) has been highlighting. Thus, the present article describes an optimization of the DLLME using low environmental impact extractor solvent to determine the chlorpyrifos insecticide in water. The analytical curves presented values for the correlation coefficient (r) higher than 0.999. The limits of detection and quantification were 0.24 and 0.80 µg L-1, respectively. There were recoveries between 93 and 97 %, with relative standard deviation (RSD) varying between 1.00 and 3.61%. The developed methods presented accurate and reliable results, are simple and safe, characteristics important for the implementation of a methodology as a routine analysis, and were applied in the determination of chlorpyrifos in water samples from five points along the Rio Dourados, near the city of Fátima do Sul.

Neste estudo, dois tipos de pirólise líquida foram realizados, uma produzida em laboratório e outra adquirida de uma companhia que fornece produtos agrícolas. As análises foram feitas por cromatografia gasosa com detecção através de ionização de chama (GC-FID) e espectrometria de massa (GC-MS). Os correspondentes perfis para as duas amostras são discutidos. Siringol, 1,2,3-trimetoxibenzeno, 2-metoxi-4-metilfenol, o-guaiacol e 5-tert-butilpirogalol foram as substâncias mais abundantes na extração ácida (ácido pirolenhoso + alcatrão solúvel). A composição dos líquidos pirolíticos foi caracterizada principalmente por metoxifenóis (guaiacol, siringol e seus derivados), fenóis, ácidos carboxílicos (C5-C17) e em uma menor quantidade para álcoois (C5-C9), cetonas (C7-C8) e aldeídos (C5-C7). Os resultados para o fertilizante foliar mostraram a presença de alcatrão solúvel e ácido pirolenhoso.

In this study, two kinds of samples of pyrolysis liquid were analyzed, one produced at laboratory and other acquired from a company that supplies agricultural inputs. The analyses were carried out by gas chromatography with flame ionization detector (GC-FID) and mass spectrometry (GC-MS). The profiles corresponding to the two samples are discussed. Syringol, 1,2,3-trimethoxybenzene, 2-metoxy-4-methylphenol, o-guaiacol and 5-tert-butylpyrogalol were the most abundant substances in the acid extract (pyroligneous acid + soluble tar). The composition of the pyrolysis liquids was mainly characterized for methoxyphenols (guaiacol, syringol and their derivatives), phenols, carboxylic acids (C5-C17) and in a smaller amount for alcohol (C5-C9), ketones (C7-C8) and aldehydes (C5-C7). The results for the foliar fertilizer showed the presence of soluble tar and pyroligneous acid.