Avaliação de combinações híbridas de melancia no Submédio São Francisco.

As cultivares de melancia no Brasil apresentam frutos de bom teor de açúcar, mas são pouco produtivas, suscetíveis a doenças (Sphaerotheca fuliginea, Didimella bryoniae e viroses) e têm frutos grandes. Considerando a existência de linhas diplóides e tetraplóides com boa homozigose e que a resistência é monogênica e dominante, foram obtidas combinações híbridas diplóides e triplóides as quais foram avaliadas em 2001 e 2002 no Campo Experimental de Bebedouro, em Petrolina-PE, utilizando-se irrigação por gotejamento no espaçamento de 3 m entre fileiras e 0,80 m entre plantas. Na colheita foram avaliados produção por planta e peso de fruto (kg), teor de sólidos solúveis (°Brix), ocamento da polpa e número de sementes perfeitas nas ombinações triplóides. A maioria das combinações híbridas apresentou mais de dez quilogramas por planta, frutos de 4 a 12 kg e teor de sólidos solúveis acima de 10 °Brix e e, portanto, muito semelhantes às testemunhas. No entanto, algumas combinações híbridas apresentaram ocamento da polpa e sementes perfeitas (combinações triplóides) necessitando continuar a seleção para esses dois caracteres.Suplemento.Edição de Resumos expandidos e palestras do 43. Congresso Brasileiro de Olericultura, Recife, jul. 2003

Métodos de extração de hidrocarbonetos policíclicos aromáticos em amostra de solo, sedimento e lodo.

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Novos sorventes baseados em Poli(Metiloctilsiloxano) sobre sílica para uso em extração em fase sólida.

This paper presents an easy and practical procedure to obtain silica-based C-8 type sorbents for use in solid-phase extraction. The materials are prepared by depositing poly(methyloctylsiloxane), PMOS, on the silica support. Two different treatments for immobilization were used: thermal treatment or gamma irradiation. Suitable recoveries were obtained after pre-concentration of dilute solutions, at the ng/L level, of a mixture of pesticides, indicating the good performance of the materials

Physicochemical composition, minerals, and pesticide residues in organic grape juices.

Demand for organic products is intensified in many countries each year. Following this trend, Brazil produces increasing volumes of organic grape juice. In this way, a survey of organic grape juices made from grapes produced according to this system was carried out where physicochemical composition, minerals, trace elements, and pesticide residues were determined. Variables related to grape juice composition were performed by physicochemical procedures; minerals and trace elements, by inductively plasma optical emission spectrometry; pesticide residues, by liquid chromatography-mass spectrometry. Main results show that the physicochemical composition of organic grape juices was in general in accordance to the Brazilian legislation. The mean concentrations of trace elements were very low, varying from 0.002 (Cd) to 0.970 (Ba) mg L?1. Pesticide residues were not detected in any sample analyzed (MRL= 10 μg L?1). These results show that the Serra Gaúcha viticultural region present conditions to produce organic grape juices, despite the adverse climate factors that occurs in some years. Nevertheless, these products should be made with grape varieties, such as the labrusca ones, less susceptibles to the main grapevine pathogens

Validação de método multirresíduo para determinação de pesticidas em alimentos empregando QuEChERs e UPLC-MS/MS.

This paper presents a practical and rapid method which was validated for simultaneous quantification and confirmation of 29 pesticides in fruits and vegetables using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples were extracted following the method known as QuEChERS. Using the developed chromatographic conditions, the pesticides can be separated in less than 9 min. Two multiple reaction monitoring (MRM) assays were used for each pesticide. Four representative matrices (lettuce, tomato, apple and grapes) were selected to investigate the effect in recoveries and precision. Typical recoveries ranged from 70-120%, with relative standard deviation (RSDs) lower than 20%