Appraisal of Pesticide Residues in Kola Nuts Obtained from Selected Markets in Southwestern, Nigeria

Aims: To assess the level of pesticide residues in kola nuts.
Study Design: Kola nuts were purchased in open markets within South Western, Nigeria.
Place and Duration of Study: The samples were obtained in markets within Oyo, Osun and Ogun States, Nigeria between November and December, 2012.
Methodology: Kola nuts were sun-dried and pulverized. 3 g of each of the pulverized samples was extracted with acetonitrile saturated with hexane. Each of the extracts was subjected to clean-up followed by pesticide residue determination using HP 5890 II Gas Chromatograph.
Results: Result show that, 50% of kola nuts samples obtained from Oyo State contained chlordane residue ranging from nd – 0.123 µg kg-1; all the samples from Osun State had chlordane residue ranging from 0.103 to 0.115 µg kg-1 while 70% of kola nuts from Ogun State had chlordane residues (nd – 0.12 µg kg-1). All samples from Ogun, Osun and Oyo States had endosulfan residues while 30 and 20% of kola nuts obtained from Osun and Ogun States had alachlor residues respectively.
Conclusion: The presence of alachlor (herbicide), endosulfan and chlordane residues in kola nuts is an indication that, kola nuts processors use hazardous pesticides in the storage of fresh kola nuts. This practice can pose serious health threat to the consumers of the commodity.