CHROMATOGRAPHIC DETERMINATION OF CONSTITUENTS OF THE GENUS COLCHICUM (LILIACEAE)

A high-performance liquid chromatographic method for the determination of colchicinoid alkaloids in plant material is described. The determination is performed separately in neutral and basic alkaloid fractions using a C-18-bonded silica column. Nine alkaloids, i.e., 3-demethylcolchicine, 2-demethylcolchicine, colchifoline, N-deacetyl-N-formylcolchicine, colchicine, cornigerine, 2-demethyldemecolcine, 3-demethyldemecolcine and demecolcine, in seven Colchicum plants were assayed. For identification of phenolic compounds, a method using gas chromatography-mass spectrometry was elaborated and twenty phenolic compounds were identified in extracts from five Colchicum species. As the presence of luteolin appeared to be of value for chemotaxonomic purposes, its simple densitometric determination was developed

The Inhibition Effect of Mad Honey on Corrosion of 2007-Type Aluminium Alloy in 3.5 % NaCl Solution

The inhibition effect of mad honey on corrosion of 2007-type aluminium alloy in 3.5 % NaCl solution was investigated by Tafel extrapolarisation (TP), electrochemical impedance spectroscopy (EIS) and dynamic electrochemical impedance spectroscopy (DEIS). All the studied parameters exhibited good anti-corrosive properties against corrosion of 2007-type aluminium alloy in the test solution; the corrosion rates decreased with the increase of the mad honey concentration. The surface morphology of the alloy was examined under scanning electron microscopy (SEM) in the absence and presence of the inhibitor. The inhibitory adsorption processes of mad honey on the 2007-type aluminium alloy surfaces conformed to the Langmuir adsorption isotherm