Assessment of some potentially toxic/essential elements in Hibiscus sabdariffa L. from selected gardens in Kano Metropolis

Abstract

Toxic elements have adverse effects on human health and therefore potentially toxic elements (PTEs) contamination in food deserves special attention. The research assessed the concentration of potentially toxic/essential elements in Hibiscus sabdariffa L. calyx sourced from five different gardens in Kano metropolis, Nigeria, using Atomic Absorption Spectrophotometry (AAS). Proximate analysis of the calyxes sample yielded 11.8% Ash content, 1.8% fat, 13.9% crude fibre, 4.2% protein, 7.1% moisture and 62.5% carbohydrate. The result of the mineral composition (essential elements) yielded the following in mg/kg of sample: K (106.5±0.2), Na (68.2±0.1), Mg (102±2.0), Ca (4.2±0.1), Fe (7.1±0.3), P (35.5±0.8).The results indicated that the concentrations of targeted PTEs in different gardens were in the range in mg/kg: Cd (0.217±0.039 - 0.020± 0.005), Ni (0.213±0.054 - 0.012± 0.001) and Pb (0.485±0.085- 0.163± 0.024). Both Cd and Ni were within acceptable limit of WHO/FAO in all samples except Pb which was above the limit set by WHO/FAO. There should be adequate monitoring of toxic metals in Hibiscus sabdariffa L. samples sourced from the gardens to prevent toxicity into the food chain causing bioaccumulation.