Validation of Efficiency Method for Heavy Metals Determination in Kola Nuts (Cola nitida Schott & Endl.) from Côte d’Ivoire
Kouadio Kan Rodrigue
Laboratory of Biochemistry and Food Science, Training and Research Unit of Biosciences, Felix Houphouët-Boigny, University of Abidjan, 22 P.O Box 582 Abidjan 22, Côte d’Ivoire.
Biego Henri
Laboratory of Biochemistry and Food Science, Training and Research Unit of Biosciences, Felix Houphouët-Boigny, University of Abidjan, 22 P.O Box 582 Abidjan 22, Côte d’Ivoire.
Nyamien Yves *
Institute of Agropastoral Management, Peleforo Gon Coulibaly University, P.O Box 1328 Korhogo, Côte d'Ivoire.
Konan Ysidor
Training and Research Unit of Biological Sciences, Peleforo Gon Coulibaly University, P.O Box 1328 Korhogo-Côte d'Ivoire.
Konan Constant
Department of Environment and Health, Eco-Epidemiology Unit, Pasteur Institute of Côte d'Ivoire, 01 P.O Box 490 Abidjan 01, Côte d'Ivoire.
Coulibaly Adama
Training and Research Unit of Biological Sciences, Peleforo Gon Coulibaly University, P.O Box 1328 Korhogo-Côte d'Ivoire.
Sidibe Daouda
Laboratory of Biochemistry and Food Science, Training and Research Unit of Biosciences, Felix Houphouët-Boigny, University of Abidjan, 22 P.O Box 582 Abidjan 22, Côte d’Ivoire.
*Author to whom correspondence should be addressed.
Abstract
Aims: The current study targets the achievement of a reliable process for the determination of heavy metal contents in kola nuts, namely cadmium, mercury, and lead, for better appreciation of the risks incurred from the consumption of such food products.
Study Design: kola nuts collected from different stakeholders (planters, collectors, stores and centers) were analyzed after the validation of the proposed analytical method.
Place and Duration of Study: Central Laboratory for Food Hygiene and Agro-Industry, LANADA in Abidjan, Côte d’Ivoire, running 2018.
Methodology: Two references were used for the validation of the analytical method, namely the French standard NF V 03-110 and the European directive 2001/22/EC. The assays were achieved with an flame Atomic Absorption Spectrophotometer (AAS). The heavy metal contents of some samples collected from different sampling place were then determined
Results: From the data, a significant regression chart was recorded for the heavy metals detection graphs, with significant correlation coefficients (R²˃ 0.99). The linearity domain was validated between 0.5 μg/L and 1.5 μg/L for cadmium, 15 μg/L and 45 μg/L for lead and from 10 μg/L to 100 μg/L for mercury. In addition, the LOD were 0.03 μg/L, 1.85 μg/L and 2.92 μg/L, while the LOQ were 0.07 μg/L, 6.52 μg/L and 3.32 μg/L for cadmium, lead and mercury, respectively. The relative standard deviations of the repeatability and reproducibility assays are below 4%, whereas standard additions of heavy metals are fully recovered, with percentages close to 100%. Contents of cadmium, lead and mercury in kola nuts are respectively valued at 22.97±9.01 μg/kg, 1065.57±613.76 μg/kg and 33.88±31.58 μg/kg from the farmers and 24.99±7.79 μg/kg, 296.51±98.18 μg/kg and 39.74±34.66 μg/kg from the storage centres.
Conclusion: This analytical method could help in ensuring effective sanitary control at different critical points of kola nut distribution channel for promoting a good management of the toxicity concerns in such products.
Keywords: Cola nitida, heavy metals, cadmium, lead, mercury, validation method.