EN
An increasing interest in determination of various macro- and microelements in medicinal plants has been observed. The majority of studies are carried out using one mineralization method without any optimization. The present study demonstrates that changes in mineralization parameters can significantly affect the recovery of the elements determined. In the study, the dried plant material was mineralized in 12 ways and iron (Fe), copper (Cu), zinc (Zn), nickel (Ni) and manganese (Mn) levels were determined. The samples were mineralized in the dry or open microwave mode as well as 10 closed microwave modes. The influence of acid amounts, irradiation power and time, addition of hydrogen peroxide and perfluoric acid was examined. All parameters were shown to be critical - good efficiency was observed with larger amounts of acid. The determined content varied significantly in the same sample and were in the ranges (ug g−1): 46–136 (Fe), 1.4–11.8 (Cu), 4.0–11.3 (Ni), 15.4–53.8 (Zn) and 9.5–67.6 (Mn). Increased irradiation resulted in the loss of copper and zinc and better recovery of nickel. The results demonstrate that such determinations should include the mineralization optimization step. [...]