Pesticide residue evaluation in major staple food items of Ethiopia using the QuEChERS method: A case study from the jimma zone
Environmental Toxicology and Chemistry
Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium; Department of Environmental Health Sciences and Technology, Jimma University, Jimma, Ethiopia
Samples of maize, teff, red pepper, and coffee (green bean and coffee bean with pulp) were collected from a local market in the Jimma Zone, Ethiopia. Samples were analyzed for the occurrence of cypermethrin, permethrin, deltamethrin, chlorpyrifos ethyl, DTT and its metabolites, and endosulfan (α, β). In the analytical procedure, the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction methodology with dispersive solid phase extraction clean up (d-SPE) technique was applied. Validation of the QuEChERS method was satisfactory. Recovery percentages of most pesticides were in the range of 70% to 120%, with good repeatability (%relative standard deviation<20). The limit of detection and limit of quantification varied between 0.001μg/g and 0.092μg/g and between 0.002μg/g and 0.307μg/g, respectively. The main pesticides detected were DDT, endosulfan, cypermethrin, and permethrin. All of the pesticides analyzed were detected in red pepper and green coffee bean. Residues of DDT in coffee pulp significantly differed (p<0.01) from other food items except for red pepper. The concentration of pesticides in the food items varied from 0.011mg/kg to 1.115mg/kg. All food items contained 1 or more pesticides. Two-thirds of the samples had residues below corresponding maximum residue limits, and the remaining one-third of samples were above the maximum residue limits. These results indicate the need for a good pesticide monitoring program to evaluate consumer risk for the Ethiopian people. Environ Toxicol Chem 2014;33:1294-1302. © 2014 SETAC.
Insecticides; Pesticide residue; Quechers; Red peppers; Staple food; Teff; Chemical contamination; 1,1 dichloro 2,2 bis(4 chlorophenyl)ethane; 1,1 dichloro 2,2 bis(4 chlorophenyl)ethylene; chlorphenotane; chlorpyrifos; cypermethrin; deltamethrin; endosulfan; permethrin; pesticide residue; concentration (composition); food policy; food quality; food safety; pesticide; public health; risk assessment; sampling; article; coffee; Ethiopia; food analysis; food contamination; grass; limit of detection; limit of quantitation; maize; measurement repeatability; monitoring; priority journal; product safety; residue analysis; solid phase extraction; sweet pepper; teff; Ethiopia; Jimma; Capsicum annuum var. annuum; Eragrostis tef; Zea mays; Pesticide residues; QuEChERS method; Red pepper; Staple food; Teff; Ethiopia; Food Analysis; Food Contamination; Limit of Detection; Linear Models; Pesticide Residues; Reproducibility of Results