No abstract

CIEF of components following sequential injection of ampholytes and the sample zone offers unique advantages for analysis. The most important one of these is the efficient separation of amphoteric compounds having pIs outside the pH range of the ampholytes applied, but the resolution of the components can be increased by an adequate setup in the injection protocol. In this study, the effect of the pH of the anolyte and catholyte on the selectivity and speed of the isoelectric focusing was investigated. Changes in the pH values significantly influenced the resolution and the length of the pH gradient, while changes in the charge state of components were also observed. Three ampholyte solutions (from different suppliers) covering only two pH units were used for the analyses of substituted nitrophenol dyes in uncoated capillary. With appropriate setup, the components, with pIs not covered by the ampholyte pH range, migrated in charged state outside the pH gradient. This phenomenon is preferable for coupling isoelectric focusing to MS detection, by evading the undesirable ion suppression effect of ampholytes.

No abstract

The work aimed to determine the potential of selenium incorporation into seeds of selected species of Ocimum spp. after fortification with a foliar solution of sodium selenate at a concentration of 50 g Se · ha−1. In a 2-year trial, the selenium content was determined by electrothermal atomic absorption method with Zeeman background correction. Modified spectrophotometric method (2,2-diphenyl-1-picrylhydrazyl [DPPH] assays) was used to rate the potential of oxidation– reduction components of basil seeds (AA). The total polyphenol content (TPC) was determined spectrophotometrically using the Folin–Ciocalteu reagent and gallic acid (GA) as the standard solution. The results of experiments showed that the selenium biofortification significantly (p < 0.05) increased the content of selenium in basil seeds (17-fold increase in comparison with controlled variant in case of Tulsi, 12-fold in ‘Cinamonette’ and 12-fold in ‘Dark Green’ when compared with control). The basil seeds represented a valuable source of polyphenols (1414.61–1681.75 μg GA · g−1 dried weight [d.w.]) with multiple times higher antioxidant activity (23.50–28.97 mmol Trolox · kg−1) in comparison with common tested horticultural crops (e.g. peas, tomato and pumpkin). Significant influence of fortification was not found in AA and TPC values. Fortification was not significantly reflected in AA and TPC values. In addition to its very strong reproductive function, healing and religious purposes, the basil seed is used as a functional food due to its high content of bioactive compounds.