Author(s): M A Umar, Zubair O O Salihu
The concentration of heavy metals (Zn, Ni, Mn, Cu, Pb, Cd, Fe and Cr) in eleven spice samples from FCT Abuja, Nigeria were determined using Flame Atomic Absorption Spectrophotometer (FAAS). Wet digestion method using nitric acid (HNO3) and perchloric acid (HClO4) was used for the digestion of the samples. The study showed differences in metal concentrations according to the type of samples, edible parts and processed form of the samples. The mean concentrations of Zn, Ni, Mn, Cu, Pb, Cd, Fe and Cr in the samples were 52.458±458, 4.37±0.459, 178.617±18.901, 15.512±1.266, 11.233±1.807, 0.428±0.067 and 516.666±78.877mg/kg respectively. In all, only the values of Pb, Cd and Fe measures above the WHO Maximum Permissible Limits (MPL) for various elements, while others are below the MPL. The daily intake for the spices sample was calculated based on a supposed average weight of 60kg body weight on consumption of 10g of spice daily. These values were then compared with the Minimum Risk Level (MRL) standard, to determine the level of risk (Effect) associated with their consumption. Only Pb shows an “ACUTE EFFECT” of its risk level in the calculated daily intake, all the others show “NO EFFECT”. Comparison of the mean concentration in (mg/kg) of total heavy metals on the parts of the plants used classified as Seeds, Rhizomes, Bulbs and Blend gives; 125.30, 267.21, 34.01, and 101.25mg/kg respectively. Further Comparison of the mean concentration in (mg/kg) of total heavy metals on the nature of the spice used whether it is processed or raw gives 161.50mg/kg and 370.13mg/kg respectively. The mean value of heavy metals in some spices in this study was also compared with mean values from other parts of the world. Among the metals, correlation analysis was also carried out.