Level of Manganese and Copper in Selected Vegetables Marketed in Kaduna Metropolis

Abstract

Vegetables containing micronutrients such as manganese and copper are widely consumed due to their essential role in the human body. Human activities due to environmental pollution significantly contribute to high levels of manganese and copper in the human body, which can lead to toxic effects. The research is aimed at determining the level of manganese and copper in selected vegetables (Lactuca sativa, Telfairia occidentalis, Vernonia amygdalina, Spinacia olaracea and Adansonia digitata) marketed in Kaduna metropolis. The selected vegetables were processed and digested using a tri-acid mixture (HNO3:HClO4:H2SO4 = 5:1:1) and the Cu and Mn content of the digests obtained was determined by Atomic Absorption Spectrometry (AAS). The results obtained indicated that Spinacia olaracea had the highest (0.336 ± 0.001) level of Mn while Telfairia occidentalis had the least (0.018 ± 0.013). The highest (0.139 ± 0.0002) level of Cu was recorded in Vernonia amygdalina and the lowest level (0.068±0.005) was found in Lactuca sativa. All the concentrations recorded are within the official WHO permissible limit of 5mg/kg for manganese and 4mg/kg for copper in vegetable plant materials. Therefore, these values may suggest that the selected vegetables are safe for human consumption.