Physico-chemical Parameters and Heavy Metals Determination in Selected Medicinal Plants Sold in ‘Yar Marina Market, Sokoto-Nigeria

The increasing prevalence of environmental pollution, especially soil contamination by heavy metals has led to their increased uptake in the human food chains through plant parts. Accumulation and magnification of heavy metals and other toxins in human tissues through consumption of herbal remedies can cause serious negative impacts on health. This study was aimed at determining the physico-chemical parameters and the levels of heavy metals (Cr, Cd, Mn, Cu, Fe, Pb, Zn and Ni) concentration in selected crude herbal plants sold in ‘Yar Marina’ Market, Sokoto-Nigeria. The physico-chemical parameters were determined using standard analytical methods and the heavy metals were determined using Atomic Absorption Spectrophotometry (AAS) after wet digestion. The results shows that moisture content is 3.67 – 4.83 %,, ash value 11.0 – 18.7 % and acid insoluble ash 1.0% 8.4 %. The result also revealed the maximum concentrations (mg/Kg) of the heavy metals in the samples as: 0.034±0.001, 14.977±0.001, 0.193±0.001, 15.160±0.002, 1.715±0.001, 0.335±0.001, 0.429±0.001 for Cd, Mn, Cu, Fe, Pb, Zn and Ni respectively. While the moisture content of the samples was excellent, ash and acid insoluble ash suggested some level of contermination probably with sand. Also, the levels of all the heavy metals analysed in the samples were found to be of acceptable limits for heavy metals in plant samples. The exception was only for manganese in Cassia singueana and Combretum micranthum leaves.. It is therefore, suggested that the quality, safety and efficacy of these medicinal plants be improved through pharmacovigilance. Keywords: Heavy Metals, Medicinal Plants, Physico-chemical and ’Yar Marina market