Now showing items 1-10 of 13
Lignoids in seedlings of Virola sebifera
(Phytochemical Analysis, 2000-11-01) [Artigo]
Quantitative analysis carried out by high performance liquid chromatography indicated the accumulation of a major secondary compound in seedlings of Virola sebifera which was isolated and identified as the lignan ...
Antifungal amides from Piper hispidum and Piper tuberculatum
(Phytochemistry, 2000-11-01) [Artigo]
Piper hispidum and Piper tuberculatum accumulate amides bearing isobutyl, pyrrolidine, dihydropyridone and piperidine moieties. The isolation and characterization of several representatives including two hitherto unreported ...
Substâncias húmicas de turfa: estudo dos parâmetros que influenciam no processo de extração alcalina
(Química Nova, 2000-08-01) [Artigo]
This study reports the parameters which influence on extraction of humic substances (HS) from peat. The yield, organic and inorganic contend, E4/E6 ratio and elemental composition (C,H,N) of the extracted HS have been ...
Effect of a pilot washing system on dicofol levels in orange matrix
(Journal of Agricultural and Food Chemistry, 2000-07-01) [Artigo]
An efficient analytical method is described for the analysis of dicofol residues in pulp and orange peel. Samples are mixed with Celite and transferred to chromatographic columns prepacked with silica gel. Dicofol is eluted ...
Rapid spot test analysis for the detection of dipyrone in pharmaceutical preparations
(Analytical Sciences, 2000-03-01) [Artigo]
Rapid determination of furanocoumarins in creams and pomades using SPE and GC
(Journal of Pharmaceutical and Biomedical Analysis, 2000-03-01) [Artigo]
A solid-phase extraction and chromatography-flame ionization detection (GC-FID) method has been developed for the routine analysis of psoralen, bergapten, isopimpinellin and pimpinellin in creams and pomades employed in ...
6-[omega-arylalkenyl]-5,6-dihydro-alpha-pyrones from Cryptocarya moschata (Lauraceae)
(Phytochemistry, 2000-04-01) [Artigo]
Eleven 6-[omega-arylalkenyl]-5,6-dihydro-alpha-pyrones, cryptomoscatones D2, E1, E2, E3 and F1 and cryptopyranmoscatones A1, A2, A3, B1, B2 and B4, in addition to goniothalamin and cryptofolione, were isolated from branch ...
Solid-phase extraction of sugar cane soot extract for analysis by gas chromatography with flame ionisation and mass spectrometric detection
(Journal of Chromatography A, 2000-08-11) [Artigo]
The incomplete combustion of biomass is one of the most important sources of emissions of organic compounds into the atmosphere, like polycyclic aromatic hydrocarbons (PAHs) which show genotoxic activity. Since environmental ...
Extraction and clean-up procedure for analysis of organochlorine pesticide residues in ethoxylated lanolin
(Farmaco, 2000-09-01) [Artigo]
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, ...
Construção e aplicação físico-química de um eletrodo de segunda espécie, sensível ao íon oxalato, em meio aquoso
(Eclética Química, 2000-01-01) [Artigo]
Este trabalho descreve a construção de um eletrodo de segunda espécie, Pt|Hg|Hg2Ox|Grafite, sensível ao íon oxalato (Ox). O eletrodo é construído facilmente, apresenta um rápido tempo de resposta, é de baixo custo, e tem ...