Investigation on bioavailability of some essential and toxic elements in medicinal herbs.

Trace and major elements were determined in medicinal herbs (Cynara scolymus, Matricaria chamomilla, Artemisia absinthium L., Achillea millefolium, and Inula britannica) as well as in rhizosphere soil samples. Based on the results obtained after microwave-acid-assisted digestion (nitric acid + hydrogen peroxide) and single-step extraction (ammonium acetate), the real and potential acidity and redox potential of the soils, uptake, mobility, and bioavailability of potassium, calcium, magnesium, iron, manganese, copper, zinc, nickel, chromium, lead, and cadmium are discussed. By calculating the bioconcentration factors and their deviation from the recommended values, elevated concentrations, were explained in terms of contamination and pollution. The concentrations measured in both plants and soil samples were below maximum allowable concentration ranges considered for the European Union.