Evaluating the Level of Essential and Non-Essential Metals on Papaya (<i>Carica Papaya</i>) and Hop (<i>Rhamnus Prinoides</i>) Plants in Gummer Woreda Gurage Zone, Central Ethiopia

Unindustrialized countries like Ethiopia; the local plants play major roles to the limited modern health care available. Therefore, the objective of the study was to evaluate essential and non-essential metals; Ca, Mn, Zn, Cu, Fe, Mg, Cd, and Pb of Hop (Rhamnus Prinoides) and Papaya (Carica papaya) which are commonly used in Gummer woreda central Ethiopia. The level of these metals cultivated were determined using flame atomic absorption spectrometry. The analysis of optimized wet digestion method which a 0.5 g sample using a mixture of 2 ml HNO<sub>3</sub> and 2 ml HClO<sub>4</sub> at 150°C for 210 minutes. The digestion was evaluated by spiking the samples and their percentage recoveries in the range of 89−103.5%. The results showed that both plants under investigation have the ability to accumulate relatively higher amounts of Ca among the determined essential metals. The concentration ranges in dry weight basis in decreasing order for the samples were: Ca (3.27-5.85 mg/kg) > Mn (1.13-3.98 mg/kg) > Zn (1.58-2.96 mg/kg) > Fe (1.17-2.79 mg/kg) > Mg (1.57- 2.54 mg/kg) > Cu (1.09-2.47 mg/kg. The concentration of Pb and Cd in the samples was below the limit of detection. All the non-essential metals analyzed in this study were below the permissible ranges presented by FAO/WHO standards. Hence, the studied plant is safe for dietary and uses with respect to the analyzed metals. Additional studies will be continued on the screening of of the plants based on phytochemical activities.