A chemometric approach to distribution of selenium in medicinal plants cultivated in poland

The aim of this study was to evaluate the level of selenium (Se) in common raw plant materials (herbs, leaves, flowers, fruits, and roots) obtained from medicinal plants cultivated in Poland. Furthermore, the relationship between the morphological part of a plant and its species was examined, and the concentration of Se in it was measured. Spectrofluorimetric determination of Se in 148 samples of 44 plant species revealed that the majority of the plants contained Se at a level from several to several tens of μg/kg dry weight (d.w.). A relatively high Se concentration, in the order of 50 μg/kg d.w., was found in Majoranae herba, Crataegi fructus, and Lini semen. An especially high Se level, >100 μg/kg d.w., was found in only three plants-Equiseti herba, Farfarae folium, and Cichorii radix. Application of a nonparametric Kruskal-Wallis analysis of variance test indicates that the morphological variable influences the level of Se in the studied groups of raw plant materials. The mean concentration of Se in fruits differs significantly from that found in flowers and roots. However, there was no statistically significant difference between the Se content in herbs and leaves and its levels in fruits, flowers, and roots. Cluster analysis and principal component analysis calculations show that it is possible to relate the Se concentration in plant material to the plant species and botanical family of the medicinal plant in only a few cases. Analysis of average Se levels in the plant species showed that the plants belonging to the Apiaceae and Labiatae botanical families are more Se-rich than those belonging to Rosaceae.