Concentration levels of selected essential and toxic metals in potato ( Solanum tuberosum L.) of West Gojjam, Amhara Region, Ethiopia

Abstract

Potato ( Solanum tuberosum L.) is one of the most widely used as a staple food crop for human diets. It is an excellent source of minerals. In this study, contents of Ca, Mg, Fe, Zn, Cd and Pb in potato cultivars cultivated in Yilmana Densa, and Mecha districts of the West Gojjam zone, Ethiopia were determined by flame atomic absorption spectrometry. A 0.50 g oven-dried potato sample was digested using a mixture of 10 mL HNO ₃:HClO ₄ (4:1 v/v) at 120 °C for 3 h. The concentration ranges in dry weight basis in decreasing order were: Mg (420–438 mg/kg) > Ca (176–254 mg/kg) > Fe (27.3–90.4 mg/kg) > Zn (20.6–77.7 mg/kg) > (2.00–17.4 mg/kg) for Pb. The toxic heavy metal Cd was below the limit of detection in all the analyzed samples (<0.1 mg/kg). The Mg found in highest contents while Fe was the most abundant microelement. The Cd was found below the provisional maximum tolerable daily intake of WHO/FAO and European Commission (EC) while Pb was above the limit. A wide range of variations was observed in the metal contents of potato cultivars collected from the two districts. Potato cultivars grown in West Gojam zone of Ethiopian could contribute a substantial amount of Fe and Zn together with the major elements, Ca and Mg to the individual’s daily dietary needs if consumed on a regular basis.