Journal of the Brazilian Chemical Society
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/13322
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Item Age and time related pheromone production in coffee leafminer Leucoptera coffeella Guérin-Méneville (Lepidoptera: Lyonetiidae)(Sociedade Brasileira de Química, 2008) Lima, Eraldo R.; Vilea, Evaldo F.; Lucia, Terezinha M. C. Della; Ataíde, Lívia M. S.This study was undertaken to access the pattern of sex pheromone production in glands of virgin females of Leucoptera coffeella as an indirect measure of the calling behavior. The major compound, 5,9-dimethylpentadecane (1) was extracted from pheromone glands of virgin females to be used in two experiments. The first one investigated the effect of the pheromone production time by females (extracts of 10 females with age of two days were carried out at 2-hour intervals). The other experiment evaluated the effect of female age on pheromone production (10 females with age ranged from 1 to 5 days after emergence class were used). Hexane extracts were made with 5 ng µL-1 of 5,9-dimethylheptadecane (2) as internal standard and analyzed by GC. Females had the highest amount of pheromone at the last four hours in the dark and the two first hours in the light period. One-day old females produced the highest amount of pheromone in the glands.Item A solid-phase microextraction method for the chromatographic determination of organophosphorus pesticides in fish, water, potatoes, guava and coffee(Sociedade Brasileira de Química, 2005) Capobiango, Helena L. V.; Cardeal, Zenilda L.This paper describes a Solid Phase Microextraction method (SPME-CG) to the determination of organophosphorus pesticides in samples of fresh-water fish, water, potatoes, guava and coffee by capillary gas chromatography with nitrogen phosphorus detector. The samples were collected from October 2002 to April 2003 in the tributaries and sub-tributaries of the Paranaiba River, which supplies the city of Patos de Minas, Minas Gerais, Brazil. The determination of the pesticides: co-ral (O,O-diethyl O-(3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl) phosphorothioate), DDVP (2,2-dichloroethenyl dimethylphosphate), disyston (O,O-diethyl S-[2-(ethylthio) ethyl] phosphorodithioate), ethion (O,O,O’,O’-tetraethyl S,S’-methylene bis(phosphorodithioate)), phorate (O,O-diethyl S-ethylthiomethyl phosphorodithioate), phosdrin (2-methoxycarbonyl-1-methylvinyl dimethyl phosphate), guthion (O,Odimethyl-S-[(4-oxo-1,2,3-benzotriazin-3(4H)-yl)methyl] phosphorodithioate)), malathion (diethyl (dimethoxy thiophosphorylthio succinate) and methyl-parathion (O,O-dimethyl O-4-nitrophenyl phosphorothioate) in samples of fish, water and others foods with a manual SPME-CG holder using a 100 μm PDMS microfiber, is simple, easy to handle and solvent-free. The optimised conditions for pesticides extraction by SPME-CG method were: sample agitation, absorption at room temperature for 40 min, desorption at 220°C for 10 min, and sample volume in the vial of 16.0 mL. Under these conditions, the analytical curves were linear in different ranges (depend of each pesticide) with correlation coefficients from 0.997 to 0.999 and the precision was good (RSD from 4.40 to 15.13%). The detection limit was 0.05 μg L-1 to 8.37 μg L-1 and the quantitation limit was 0.09 μg L-1 to 8.70 μg L-1. The method was employed to detect and quantify pesticides in 24 fish of three different species and also in water, potatoes, guava and coffee. The samples analyzed showed residues of six different organophosphorus pesticides.