Determination of some heavy metals in spinach and lettuce from selected markets in Kaduna metropolis

Abstract

Heavy metals such as copper, zinc, cadmium and lead were analyzed in vegetable samples (lettuce and spinach) obtained from ten major markets within Kaduna metropolis. The samples were digested by dry-ashing techniques and the trace metal were determined using atomic Absorption Spectrophotometry (AAS). The result were compared with the standard set by FAO/WHO (2001) which shows that for spinach sample cadmium and lead are within the permissible limit with the exception of Gumi market with (Cd 0.30 mg/kg). zinc was found to be within the acceptable limit for all spinach sample obtained. Copper was found to have exceeded the stipulated standard in all spinach samples except for sample from Angwan Rimi market with (0.06mg/kg). for lettuce sample, cadmium and zinc were found to be within the stipulated limit. Analysis for copper in the lettuce sample clearly show that samples from all other markets exceeded the acceptable limit, except samples from Gumi and Sabo markets with (0.32mg/kg and 0.32mg/kg) respectively. From the stipulated limits set by WHO/FAO, consumers of vegetables from this study areas were likely to be liable to copper toxicity and some few metals as stated above.