ICP_OES determination of essential, trace essential, and non-essential elements in the anatomical parts of medicinal herb (Pentas Schimperiana) grown in Wolaita Zone, Ethiopia

Abstract

This study aimed to evaluate the distribution of heavy metals (essential, trace essential, and non-essential) in medicinal herb (Pentas Schimperiana) roots, stem bark, and leaf samples collected from different geographical locations. A dry ashing followed by a wet digestion procedure involving the use of a mixture of strong acids (6 M HCl + 0.1 M HNO3) was used for plant sample preparation. Inductively coupled plasma optical emission spectroscopy assessed 18 elements in the anatomical parts (root, stem bark, and leaves) in replicates. Based on the results, the highest concentrations of macro-elements (essential), Ca, K, Mg, Na, and P were obtained in the stem bark of Pentas Shimperiana collected from the Damot Gale district while higher content of S was determined in the leaf part of the plant from a similar location. However, Fe was found to be the dominant microelement in the stem bark followed by Zn. Similarly, the distribution of macro-elements from high to low levels obtained in the stembark of the plant was in the order of K, Ca, P, Mg, Na, and S, respectively. The results indicate that the content of most metals studied did not exceed the permissible limit for medicinal plants set by World Health Organization (WHO).

Keywords

• Trace essential metal
• Non-essential metals
• Essential metal
• Pentas Schimperiana
• ICP_OES