Buscar
Mostrando ítems 31-40 de 341
Extraction and clean-up procedure for analysis of organochlorine pesticide residues in ethoxylated lanolin
(Elsevier B.V., 2000-09-01)
In the present study an evaluation was made of a method for the determination of organochlorine pesticide residues in ethoxylated lanolin. Samples were homogenized with Celite, transferred to chromatographic columns, ...
Metodologia rápida e eficiente para análise de pesticidas organoclorados em fubá
(Soc Brasileira Quimica, 1996-11-01)
A rapid and efficient analytical method is presented for the quantitative analysis of 10 organochlorine pesticides in corn meal. The extraction and clean up steps are combined into one step by transferring the sample to a ...
Cromatografia gasosa ultrarrápida: uma visão geral sobre parâmetros, instrumentação e aplicações
(Sociedade Brasileira de Química, 2010-01-01)
Since the introduction of GC there has been an ongoing interest in reducing time of analysis resulting in new terms and definitions such as ultra fast gas chromatography (UF-GC). One of the most used definitions describes ...
Determination of pentachlorophenol in drinking water
(1997-12-01)
In this study, an in situ derivatization and extraction method for the determination of pentachlorophenol (PCP) has been applied successfully in the analysis of water samples. The PCP derivative analysis was performed by ...
Electrophysiological responses of Atta sexdens rubropilosa workers to essential oils of Eucalyptus and its chemical composition
(2006-09-01)
The leaf-cutting ant Atta sexdens rubropilosa Forel, 1908 is the most harmful of the Eucalyptus pests, causing severe losses in wood production through defoliation. Various strategies have been tried and effort spent on ...
Phytochemical evidence for the plant origin of Brazilian propolis from Sao Paulo state
(1999-05-01)
Propolis and plant secretions from three species, most frequently mentioned as botanical sources of the bee glue in Brazil (Baccharis dracunculifolia, Araucaria angustifolia and Eucalyptus citriodora) have been investigated ...
Droplet counter-current chromatography of indole alkaloids from Tabernaemontana hilariana
(Wiley-Blackwell, 1999-03-01)
This paper reports the separation of the indole alkaloids from the benzene extract of the root barks of Tabernaemontana hilariana (Apocynaceae). The crude alkaloid fraction was fractionated by droplet counter-current ...
OLEO ESSENCIAL EM ALGUMAS ESPECIES DE EUCALYPTUS
(1995-08-31)
In this work we used leaves of four species of Eucalyptus - E. bicostata Maiden, E. deanei Maiden, E. dunnii Maiden and E. viminalis Labill, grown in Colombo, Parana State, Brazil. Preliminary studies were done, in the ...