Determination of mineral elements content in Teucrium chamaedrys L. herb and herbal dust aqueous extracts obtained by ultrasound-assisted extraction

Wall germander (Teucrium chamaedrys L., Lamiaceae) is an aromatic medicinal plant widely used in folk medicine. Beyond its ethnopharmacological value, it tends to accumulate specific minerals selectively. Consequently, rigorous quality control of its products is essential before they are placed on the market. Monitoring the presence of heavy metals is particularly critical, as these elements can accumulate in human and animal tissues, leading to significant health issues. The goal of the present study was to determine the elemental composition (K, Ca, P , S, Mg, Na, Si, Cu, Zn, Sr, Ba, Fe, Li, Mn, Bi, Ag, B, CE, Cr, Co, Ni, As, Cd, Pb, Tl, and Hg) of wall germander aqueous extracts. These extracts were produced from both the aerial part (herb) and the herbal dust (a by-product of tea processing). Ultrasound-assisted extraction was employed under the following next conditions: distilled water as the solvent, a constant temperature of 50 °C, a liquid-to-solid ratio of 15 mL/g, and an ultrasonic power of 150 W, with varying time intervals (10, 20, and 30 min). Following wet digestion, the elemental concentrations (expressed in mg/L) were evaluated using Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES). All extracts exhibited high concentrations of K, followed by P and Ca. The results indicated that aqueous extracts from both the herb and herbal dust obtained after 20 minutes contained the highest mineral content, suggesting that this extraction duration is the most efficient and suitable for producing extracts intended for human consumption.