Interlaboratory Comparison Exercise for the Determination of Copper and Lead in Ghana
Determination of metals in the environment is of great interest due to their harmful effect on human health. In Ghana, monitoring of these metals in food is undertaken and regulated by the Food and Drugs Authority. The recommended maximum residual limit of copper (Cu) and lead (Pb) in food is 2 and 0.01 mg/L, respectively. This project presents a survey on various laboratories where metal analysis can be conducted in Ghana and the results of an inter laboratory comparison exercise for the determination of heavy metals of concern to human health. In all, 15 laboratories were identified in Ghana and four of these laboratories participated in the comparison exercise using atomic absorption spectrometry (AAS) for
metal determination. Each was asked to analyze four test samples, two standards of 0.5 ppm and 2 ppm. Of the 15 laboratories identified, six (40 %) were in Greater Accra Region, six (40%) in Ashanti Region, two in Western Region and one in the Eastern Region of Ghana. The recovery obtained by the four laboratories ranged from 374 to 113.5%. The exercise revealed that only 50% of the laboratories met the minimum acceptable recovery target; hence their results could be accurate.