DETERMINATION OF SELECTED MACRO AND TRACE ELEMENTS IN TWO GREEN LEAFY VEGETABLES: SPINACIA OLERACEA (SPINACH) AND CORCHORUS OLITORIUS (JUTE LEAF) COMMONLY CONSUMED IN SHANGO, MINNA, NIGER STATE.

Abstract

Vegetable is a nutritionally valuable food with very complex chemical composition and whose elemental contents is affected by the area they were cultivated. It can accumulate toxic metals, which may present hazards to human health. The aim of the study was to determine the concentration of some ten heavy or essential metals (Co, Cr, Cu, Fe, Mn, Zn, Ca, K, Mg & Na) present in two green leafy vegetables: Spinacia oleracea (Spinach) and Corchorus olitorius (Jute Leaf) consumed in Shango Minna, Niger State, Nigeria; using Atomic Absorption Spectrophotometer. Zero concentration was recorded for Co in both samples, while the highest mean concentrations recorded in Spinacia oleracea were for K, Ca, and Na (550.0±0.0000 ppm, 389.1995±0.0021 ppm, and 235.5±0.0000 ppm respectively). Similarly, the highest mean concentration recorded in Corchorus olitorius were for K, Ca, and Na (150.0 ± 0.0000 ppm, 142.326±0.0045 ppm, and 103.5±0.0000 ppm respectively). The mean concentration for the other determined elements (Cr, Cu, Fe, Mn, Zn & Mg) in Spinacia oleracea were 0.0500±0.0004 ppm, 0.0775±0.0007 ppm, 4.937±0.0005 ppm, 5.0425±0.0007 ppm, 0.616±0.0005 ppm and 198.9605±0.0018 ppm respectively; and 0.066±0.0006 ppm, 0.183±0.0002 ppm, 6.038±0.0009 ppm, 1.119±0.0015 ppm, 0.4135±0.0007 ppm and 48.375±0.0037 ppm respectively in Corchorus olitorius. The analytical data shows a good level of quality of the analysed vegetable samples, especially with regards to the absence or low concentration of toxic elements (like Co and Cr) and significant amount of trace/major elements (K, Ca, Mg & Na) with little of Cu and Zn. It was recommended among others that people should be sensitized about possible contamination and the need for regular monitoring of levels of these metals in vegetables to minimize or prevent ingestion through the food chain.