Assessment of trace metals and physicochemical parameters of commercially available honey in Ethiopia

Abstract

Trace metal contents and quality parameters (physicochemical properties) such as pH, electrical conductivity and ash content of four Ethiopian honeys were determined using flame atomic absorption spectrometry, pH-meter, conductivity meter and ashing, respectively. The optimized wet digestion method for honey analysis was found efficient for the metals determined and it was validated through the recovery experiment and a good percentage recovery was obtained (93-104%). Fe was found in highest amount with mean concentration ranging from 5.37 to 12.4 μg/g followed by Ni with mean concentration range of 0.80 to 4.46 μg/g, Cr (1.20-4.33 μg/g), Zn (1.92-4.22 μg/g), Co (0.60-1.17 μg/g), Mn (0.16-0.89 μg/g), Cd (ND-0.69 μg/g) and Cu (0.09-0.47 μg/g). The toxic metal Pb was not detected. The ranges of physicochemical properties determined were summarized as: pH 4.11-4.33, electrical conductivity of 0.10-0.29 mscm-1 and ash content 0.17-0.46%. The metals content and the physicochemical properties investigated in honey samples were found within the ranges established by national and international standards.