Levels of organochlorine pesticides in onion and tomato samples from selected towns of Jimma Zone, Ethiopia
Umeta Jirata, Tsegaye Girma Asere, Yerosan Buzayo Balcha, Abera Gure
Abstract
<h2>Abstract</h2> This study aimed to determine residues of organochlorine pesticides (OCPs) in tomato and onion samples collected from selected markets in the Jimma zone. A QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method was used for sample preparation followed by gas chromatography-mass spectrometry (GC-MS) for OCPs analysis. The method used showed wide linear ranges from 5-50 μg/L for all eight pesticides, with R<sup>2</sup> values ≥ 0.992. The LOD values for the pesticides tested ranged from 0.14 μg/kg for p,p'-DDE to 2.40 μg/kg for p,p-DDT. LOQ values ranged from 0.46 μg/kg for p,p-DDE to 8.32 μg/kg for p,p'-DDT. The recoveries ranged from 74.84 – 109.45 % except for β-BHC (67.82 %). While most of the OCPs in the onion and tomato samples met European Union (EU) and Codex standards, some exceeded the limits. Methoxychlor and p,p'-DDT in onions, and methoxychlor, p,p'-DDT, α-BHC, and δ-BHC in some tomatoes, were detected above the permitted levels. Specific OCPs were not detected in some samples including aldrin in Meki Tomato (Mek-T), γ-chlordane in Agaro Tomato (Ag-T), and p,p'-DDE in Gera Tomato (Ger-T). The residual concentrations of OCPs varied among the samples. Among tomatoes, Gera had the highest percentage of detected OCPs contaminants (37 %), followed by Agaro (34.34 %) and Meki (28.55 %). Similarly, Sire onion (SrO) had the highest percentage of detected OCPs (28 %) compared to Minjer (25.16 %), Shewa Robit (25.10 %), and Sudan onion (22.25 %). In conclusion, most tomato and onion samples analyzed in this study contained OCP residues highlighting the importance of conducting a consumer health risk assessment.