Determination of Pesticide Residues in Edible Crops and Soil from University of Agriculture Makurdi Farm Nigeria

Aims: To extract pesticide residues in some edible crops and soils from farm lands so as to determine their concentration in order to assess their safety status

Study Design: Solid-Phase extraction technique was used to extract pesticides content mainly of organochlorine class from some edible crop plants and soils as well as determining some main physicochemical parameters of the soils.

Place and Duration of Research: University of Agriculture, Makurdi commercial crop farms from in the month of July, 2015.

Methodology: Pesticide residues were extracted from edible crops (Daucus carota, Capsicum Anuum, Telfairia occidentalis, Solanum lycopersicum, Amaranthus hybridus, Solanum macrocarpon) and soils using dispersive solid-phase extraction method. The extracts were analysed using GC-MS technique

Results: The mean concentration (mg/kg) of pesticides in soil samples were 12.1 ± 0.1, 0.09 ± 0.02, 0.12 ± 0.02, 14.9 ± 0.2 and 5.05 ± 0.2 for butachlor, aldrin, dieldrin, pendimethalin and propanil, respectively. Pesticides concentration in vegetables (μg/kg) generally ranged from 0.001 ± 0 - 1.64 ± 0.6, the highest value being cypermethrin and the least alpha-HCH. Their concentrations in each sample ranged in this order; D. carota (1.62 ± 0.01- 0.001 ± 0); C. Anuum (1.63 ± 0.7 - 0.002 ± 0.001); T. occidentalis (1.64 ± 0.6 - 0.001 ± 0.001); S. lycopersicum (0.84 ± 0.7 - 0.002 ± 0.01); A. Hybridus (1.61 ± 0.5 - 0.001 ± 0); S. macrocarpon (1.62 ± 0.01 - 0.001 ± 0), respectively.

Conclusion: Cypermethrin showed the highest concentration values in all vegetable samples while alpa-HCH has the least. Although all samples showed values within WHO maximum residue limits (MRLs) for spices, indicating that they are transiently safe, but it is necessary to have prolonged seasonal monitoring.