Heavy metal contents in Veronica species and soil from mountain areas in Serbia

This paper describes the relationships between concentrations of selected trace elements in soil and their bioaccumulation in aerial parts of three Veronica species (Plantaginaceae). Plant and soil samples were collected from three mountainous areas in Serbia, prepared by microwave acid-assisted digestion and analyzed by flame and flameless atomic absorption spectrometry. Total concentrations of Cu, Zn, Mn, Fe and Cr in the soil varied from 12.38 to 47.77, 62.78 to 138.00, 517.58 to 1675.78, 13574.22 to 35920.00 and 36.18 to 115.15 mg/kg, while those in the plants ranged from 6.04 to 12.8, 27.66 to 58.01, 25.38 to 89.25, 35.53 to 563.26 and 0.44 to 18.96 mg/kg, respectively. There were no significant differences in heavy metal concentrations between tested Veronica species from the same location, indicating that their heavy metal uptake pattern was not species specific. In the case of Mn, despite its wide variation in soil, concentrations in plant samples were uniform, which suggests potential ability of tested species to control Mn uptake or translocation to upper plant parts. Additionally, the lowest concentrations of Cu were obtained in plant samples collected from soil with the highest Fe concentrations, pointing out that Cu availability to plants might be reduced due to high Fe content in soil solution.

Trace elements in aerial parts and rhizosphere of Thymus pannonicus All.

This paper brings out the results of the study on the levels of selected trace elements (Cu, Fe, Mn, Zn and Cr) in aerial parts of Thymus pannonicus All. (Lamiaceae) and rhizosphere soil from twelve locations in Serbia. Prior to assays by flame and flameless atomic absorption spectrometry, samples were subjected to microwave-assisted acid digestion. Real and potential acidity of soil samples were also measured. Obtained results for soil samples, although slightly higher for some elements (Cu: 12.38–45.18 mg/kg; Fe: 22102–46193 mg/kg; Mn: 776.95–4901.27 mg/kg; Zn: 62.27–214.02 mg/kg; Cr: 48.86–69.13 mg/kg), were found to fit into biogeochemical background. Element contents in plant samples differed depending on collecting site (Cu: 5.26–14.07 mg/kg; Fe: 25.92–1454.07 mg/kg; Mn: 89.29–278.25 mg/kg; Zn: 1.81–10.64 mg/kg; Cr: 1.11–3.51 mg/kg), which can be partly explainable by different nutrient availability influenced by soil acidity. Zinc levels in T. pannonicus were below expected and seem to be strongly influenced by plant physiological properties.

Differential Accumulation of Gold and other Metals by Plants

Using flameless atomic absorption spectrometry was studied the accumulation of gold and other toxic metals (copper, zinc) by horsetail (Equisetum arvense) in comparison with milfoil (Achillea millefolium). Plant samples were collected from Ro�ia Montan� district in Carpathian Mountains, Romania. In this area gold was extracted for a long time during Roman Empire. Presently, the quantity of gold is diminished and the actual tendency to obtain gold by cyanide technique is very dangerous for the environment. Using horsetail and milfoil as biological prospectors it can be observed the preferential accumulation of gold by horsetail. The aim of this study is to demonstrate the accumulation of gold in the plants of Ro�ia Montan� area in important quantities compared with other metals concentration induced by the thousands of years of exploitation. The reserves of gold remained in the soil are not important to develop an industrial production, very dangerous for the environment.

Spuriously Low Concentrations of Serum Iron Measured with Generation 14 Kodak Ektachem Slides: Prevalence, Possible Causes, and Partial Improvement with Generation 16 Slides

For sera with iron (Fe) concentrations < 4 mumol/L, Kodak Ektachem slides Generation (GEN) 14 (without ascorbic acid) yielded systematically lower results for Fe than did liquid Ferrozine-based reagents from Baker containing ascorbic acid (10 g/L, final concentration) and adapted to Cobas-Bio. During an 8-month comparison period, outliers (defined as [Fe]Cobas - [Fe]Kodak > 4 mumol/L) were seen in 21 of the 8731 sera (0.24%) tested, corresponding to < 5% of the sera with [Fe]Kodak < 4 mumol/L. In vitro addition of ascorbic acid and (or) Fe identified at least two types of outliers: type 1 (approximately 70%), characterized by [Fe]Kodak > 0.4 mumol/L, by (supra)normal Fe recovery in Kodak slides in the presence or absence of ascorbic acid (10 g/L), and by between-method differences in serum Fe (Cobas - Kodak) that were significantly correlated with serum Zn content (P < 0.0004); and type 2 (approximately 30%), tentatively ascribed to contamination by EDTA, with serum Fe by Kodak < 0.4 mumol/L and Fe recovery near 0%, both of which could be significantly and dose-dependently increased by addition of ascorbic acid (5-20 g/L). For both types of outliers, flameless atomic absorption spectrometry (AAS) yielded results that were significantly higher than concentrations by Kodak with GEN 14. Use of GEN 16 slides (containing ascorbic acid) improved concordance of Kodak results with Cobas, and hence with flameless AAS, for both types of outliers; abolished Zn dependency of results; and increased Fe results in sera with type 2 outliers, although these remained substantially lower than by Cobas. However, like other ascorbic acid-containing reagents, GEN 16 slides were more sensitive to interference by dextran-bound Fe, as assessed during in vitro addition experiments and comparisons involving samples from Fe-dextran-treated patients. GEN 16 slides are hence expected to more frequently overestimate the physiologically available protein-bound Fe in hemodialysis patients. In hospital laboratories, this new interference will probably arise more frequently than the spuriously low results with GEN 14, hence warranting further efforts in optimizing Fe slides.