Elemental characterisation of the medical herbs Salvia officinalis L. and Teucrium montanum L. grown in Croatia

In the presented study samples of sage (Salvia officinalis L) and mountain germander (Teucrium montanum L) as well as infusions prepared from them were investigated for their mineral composition ranging from trace to major elements. Element concentrations in the medical herbs and their infusions were determined by ICP-AES. The following elements were studied: Al, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr, and Zn. Blossoms and leaves of the herb samples were digested in a microwave oven in order to determine the total content of the elements of interest. Infusions were prepared using distilled water of different temperature and applying various decoction times. The extraction yields for all elements present in the infusions were calculated. The essential elements Al, Cu, Fe, Mn, Ni, and Zn are present in the whole overground herb and infusions at concentration levels of μg/L, whereas Ca, K, Mg, and Na in mg/L. The toxic elements Cd and Pb were found only in the whole overground herb at very low concentrations, but not in the final infusions. High amounts of K, Mg, and Na in the resulting infusions justify the use of this herb as nutritional supplement in addition to the organic compounds.

► The elemental pattern of two commonly used medicinal herbs (sage and mountain germander) were determined. ► All metal concentrations were registered using ICP-AES. ► Infusions were prepared from both plants and there elemental content quantified. ► The extraction behaviour was optimised and the extraction yields were calculated. ► The knowledge of the mineral contents of medicinal herbs is important for nutritional aspects.