Investigation of major, toxic, and trace element contents and mineral safety index (MSI) of parts of <i>Elaeagnus angustifolia</i> L. and total element contents in the soil using the ICP OES technique

Alternative medicine, perfumery, animal feed, and beverages use Elaeagnus angustifolia L. (Russian olive). Therefore, it is essential to determine the major, trace, and potentially toxic element (PTE) contents of the leaves and fruits of this plant. Moreover, the mineral composition of the soil may influence its elemental distribution. In this study, the content of major, essential trace, and potentially toxic elements (PTEs) in the leaf and fruit components (skin, pulp, and seed) of Russian olives and soil minerals was determined. Inductively coupled plasma optical emission spectroscopy (ICP OES) was used to measure the concentrations of major elements (Ca, K, Mg, Na, and P), essential trace elements (Fe, Cu, Mn, Zn, Cr, Co, Ni, Se, Sn, and V), and potentially toxic trace elements (Ag, As, Ba, Cd, and Pb) in Russian olive parts and soil samples. For the solubilization process, the microwave-assisted wet digestion technique was used on plant and soil samples. Additionally, the mineral ratio and mineral safety index (MSI) of these parts were calculated. Regarding mineral ratios and MSI, all plant parts were satisfactory in Ca/P but very low in Na/K. Furthermore, while leaf and pulp [K/Ca+Mg] were greater than the ideal value (2.2), the seed was found to be below this value. All samples were above 1.0 for Ca/Mg and below 500 for Zn/Cd. Moreover, Mg and Fe were overloaded in all parts of the plant. On the other hand, the findings show that the quantified plant parts have different concentrations of major, trace, and toxic elements. The components of Russian olive contained higher amounts of Mg, Ca, Na, and P compared to other elements. The seed contained only As, while the pulp was the only source of Se. However, Ag values were found to be well above the limit values in plant parts. ICP OES precisely measured element concentrations in plant and soil samples. This study provides important details about the different parts of E. angustifolia in terms of elements that will help to understand their pharmacological, toxicological, and nutritional uses.