Levels of major and trace metals in eggplant and soil

Abstract

ABSTRACT. Eggplant is one of the widely used edible vegetables in the world including Ethiopia. The aim of this study was to determine the metal contents of eggplants and their corresponding soils collected from five different areas of Ethiopia. Levels of nine selected metals (Na, Ca, Mn, Fe, Cu, Ni, Zn, Pb and Cd) were determined using flame atomic absorption spectrometry. The mean concentration ranges (mg/kg) of the metals in eggplant were Na (1,384-1,917) > Ca (110-158) > Fe (55.9-94.8) > Mn (34.5-44.2) > Zn (17.9-29.2) > Cu (4.3-10.0) > Pb (1.8-4.5) and in soil Fe (4,714-5,508) > Na (843-1,120) > Ca (237-788), Mn (617-763) > Zn (50.7-99.4) > Cu (44.8-74.0) > Pb (13.8-15.8), respectively. Ni and Cd were below the detection limit. The results indicated that eggplant is a good source of essential macro and micro metals. It is also free from toxic metal Cd. However, it contains higher level of Pb, well above the WHO/FAO permissible level. The bioavailability of the metals in eggplant was investigated by analysis of soil pH, electrical conductivity, total dissolved solid and salinity. Transfer factor exhibited a higher accumulation of Na from the soil to the eggplant but for the other metals it was < 1.

KEY WORDS: Eggplant, Minerals, Soil properties, Transfer factor, Ethiopia

Bull. Chem. Soc. Ethiop. 2021, 35(2), 243-255.

DOI: https://dx.doi.org/10.4314/bcse.v35i2.3