DETERMINATION OF ESSENTIAL AND HEAVY METALS IN KENYAN HONEY BY ATOMIC ABSORPTION AND EMISSION SPECTROSCOPY

Abstract

Due to the nutritive and medicinal value of honey for both man and animals, qualitative and quantitative analyses of the minerals is of great importance. Heavy metals and high concentration of essential metals can be toxic both to man and animals. Rapid increase in industrialisation in Kenya has led to environmental pollution, hence increase of these metals in honey. In this project, honey samples collected from different parts of Kenya, namely, Laikipia, Baringo, Nairobi, Ngong, Mbeere, Embu, Kitui, Kibwezi and Lamu were analysed to determine the levels of selected heavy metals (Pb, Cd, Zn, Cu, As) and essential metals (K, Na, Ca, Mg, Fe). The samples were analysed using flame atomic absorption spectroscopy (FAAS) and flame atomic emission spectroscopy (FAES). Hydride generation atomic absorption spectroscopy (HG - AAS) was used to determine arsenic. Results obtained from this study showed that K, Na, Ca and Mg had mean values ranged from 781.52±0.09 to 172.83±0.02ppm, 269.1 to 98.04±0.03 ppm, 70.17±3.9ppm to 19.33±4.07 ppm and 41.88 ±0.92 to 12.64 ±0.43ppm respectively. Most of the samples had a high level of Zn with mean value 0.19±0.06ppm followed by Pb with of mean value 0.16±0.10ppm, then Cu with a mean value of 0.02±0.01 ppm followed by Cd with a mean value of 0.02±0.01ppm and finallyAs with a mean value of 0.01±0.01ppm. The concentration of Pb in most samples was found to be above the World Health Organisation (WHO) and Kenya Bureau of Standards (KEBS) limits of 0.1 ppm in food products.