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A two-column solid phase extraction was used to determine the operationally defined speciation of Cu in lager beers and red wines. Applying a nonionic macroreticular adsorbing resin Amberlite XAD-16 and a gel type strong cation exchange resin Dowex 50Wx8-200, three different groupings of the chemical forms of Cu, including the hydrophobic, the cationic, and the residual species fractions, were separated and determined. The total content of Cu in the analyzed samples and its concentrations in the distinguished fractions were measured using flame atomic absorption spectrometry without any special preparation of the sample solutions. It was found that the residual species (72-82% of the total content), being polar and noncationic forms of Cu, are the most abundant fraction of Cu in the analyzed beers. In the case of wines, the fraction of the hydrophobic species was established to have the highest share in the total Cu content, that is, 27-77%. This fraction was presumed to contain relatively strong complexes of Cu with various flavonoids and other polyphenols.

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To reveal the antixenosis potential against the pea aphid Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae) we analyzed the pea aphid survival and probing behavior, and the quantitative and qualitative variation of flavonoids in the leaves of selected soybean Glycine max (L.) Merr (Fabaceae) cultivars ‘Aldana’, ‘Annushka’, ‘Augusta’, ‘Madlen’, ‘Mavka’, ‘Simona’, ‘Violetta’, and ‘Viorica’. Aphid survival was drastically impeded on all cultivars. The electronic monitoring of aphid probing using the Electrical Penetration Graph (EPG) technique revealed that on all soybean cultivars, A. pisum readily probed into leaf tissues but the probes were usually terminated before reaching vascular tissues, which demonstrates the activity of antixenosis mechanisms in peripheral tissues epidermis and/or mesophyll in soybean leaves. The potency of antixenosis factors differed among soybean cultivars, which was reflected in differences in aphid survival and frequency and duration of phloem sap ingestion. Seven flavonoids were found: apigenin, daidzein, genistein, glycitein, isorhamnetin, kaempferol, and rutin, which occurred in different amount and proportion in individual cultivars. The content of apigenin and genistein in all soybean cultivars studied probably made them relatively unacceptable to A. pisum. Kaempferol in ‘Aldana’ might be responsible for the observed strong antixenosis resistance of this cultivar to A. pisum. The results of our survey provide the first detailed data that can be used for future studies.