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Kinga Drzewiecka, Klaudia Borowiak, Mirosław Mleczek, Iwona Zawada and Piotr Goliński

Cadmium and Lead Accumulation in Two Littoral Plants of Five Lakes in Poznan, Poland

We measured cadmium and lead concentrations in two littoral plants (Phragmites australis Cav. Trin ex. Steudel and Typha angustifolia L.) collected in June and September 2007 from five selected lakes in the Poznan city area, and also in sediment and water samples from the same places. We determined the metal concentrations in rhizomes and leaves, and in sediment and water from the littoral and near the bank zone. Only low levels of the heavy metals were found. Pb and Cd concentrations were higher in water collected from the bank zone than from the littoral zone. Pb and Cd accumulation was noted in sediments. Heavy metal levels were higher in rhizomes than in stems and leaves. The studied aquatic macrophytes may be bioaccumulators and bioindicators of Pb and Cd in freshwater in natural conditions, even when concentrations are low.

Open access

Katerina Makarova, Kinga Drązikowska, Beata Suska, Katarzyna Zawada and Iwona Wawer

Abstract

In the present work, we report the results of a spin trapping ESR study of four essential oils widely used for skin care products such as creams and bath salts. The studied essential oils are Rosmarini aetheroleum (rosemary), Menthae piperitae aetheroleum (mint), Lavandulae aetheroleum (lavender), and Thymi aetheroleum (thyme). Fenton reaction in the presence of ethanol was used to generate free radicals. The N-tert-butyl-α-phenylnitrone (PBN) was used as a spin trap. In the Fenton reaction, the rosemary oil had the lowest effect on radical adduct formation as compared to the reference Fenton system. Since essential oils are known to be lipid soluble, we also conducted studies of essential oils in Fenton reaction in the presence of lipids. Two model lipids were used, namely 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). The obtained results suggested that in the presence of DOPC lipids, the OH and PBN/CHCH3(OH) radicals are formed in both phases, that is, water and lipids, and all the studied essential oils affected the Fenton reaction in a similar way. Whereas, in the DPPC system, the additional type of PBN/X (aN = 16.1 G, aH = 2.9 G) radical adduct was generated. DFT calculations of hyperfine splittings were performed at B3LYP/6-311+G(d,p)/EPR-II level of theory for the set of c-centered PBN adducts in order to identify PBN/X radical.