Distribution of Minerals and Some Heavy Metals in the Leaves and Stems of Salvia, Ziziphus, Thyme, and Artemisia Plants

Abstract

Depending on the species and the organ of the plant, medicinal and aromatic plants can vary significantly in their mineral make-up. This experiment compared sodium (Na), potassium (K), iron (Fe), zinc (Zn), copper (Cu), and manganese (Mn) in the leaves and stems of Salvia, Ziziphus, thyme and Artemisia growing in the Al-Jabal Al-Akhdar region of Libya in spring 2024. Measurement of sodium and potassium was done by flame photometry, and Fe, Zn, Cu, and Mn by atomic absorption spectrometry, after acid digestion. The most common macro element in all the samples was potassium. It had a mean concentration of 4.98 ± 0.84 mg/g in leaves and 5.39 ± 1.20 mg/g in stems, versus 1.28 ± 1.09 and 0.897 ± 0.485 mg/g in sodium, respectively. The mean concentration of the trace elements in both organs had the same order: Mn > Zn > Cu > Fe. Artemisia leaves had the highest Na (2.84 mg/g), Zn (37.07 µg/g), Cu (15.09 µg/g) and Mn (66.39 µg/g) and Salvia leaves had the highest K concentration (5.57 mg/g). Artemisia had the highest K (6.53 mg/g), Zn (18.27 µg/g), and Cu (9.21 µg/g), Ziziphus the highest Mn (77.50 µg/g) and thyme the highest Fe (1.02 µg/g). The findings show apparent species- and organ-based variations in the distribution of elements. Since no analytical replicates, recovery, detection limits or certified reference-material results are reported in the dataset, the results should be considered as descriptive and cannot be used independently to determine dietary adequacy, toxicity, or safety.