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

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 to both man and animals. Rapid increase in industrialization in Kenya has led to environmental pollution, hence increase of these metals in honey. In this study, honey samples collected from different parts of Kenya, namely, Laikipia, Baringo, Naiorobi, Ngong, Mbeere, Embu, Kitui, Kibwezi and Lamu were analyzed to determine the levels of selected heavy metals (Pb, Cd,Zn, Cu, As) and essential metals (K, Na, ca, Mg, Fe). The samples were analyzed 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 mean values ranged from 781.52±0.09 to 172.83±0.02 ppm, 269.1 to 98.04±0.03 ppm, 70.17±3.9 ppm to 19.33±4.07 ppm and 41.88±0.92 to 12.64±0.43 ppm respectively. Most of the samples had high level of Zn with mean value of 0.19±0.06 ppm followed by Pb with mean value of 0.16±0.10 ppm, then Cu with mean value of 0.02±0.01 ppm followed by Cd with mean value of 0.02±0.01 ppm and finally As with mean value of 0.01±0.01 ppm. The concentration of Pb in most samples was found to be above the World Health Organization (WHO) and Kenya Bureau of Standards (KEBS) limits of 0.1 ppm in food products.
Keywords: Honey, heavy metals, essential metals, atomic spectroscopy.