Analysis of pesticide residues in fruits and vegetables using gas chromatography-mass spectrometry: a case from West Omo and Bench-Sheko Zone, Southwest Ethiopia

Abstract

ABSTRACT Uncontrolled use of pesticides could result in contamination of air, water, food, and ecosystems. This study aimed to determine pesticide residues in fruits and vegetables collected from selected farmlands of southwest Ethiopia from the end of April 2019 until mid of May 2019. The samples were extracted using a quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and clean-up method. Quantitative analysis of four organophosphorus pesticides (OPPs) and seven organochlorine pesticides (OCPs) were conducted using gas chromatography-mass spectrometry. All the fruit and vegetable samples obtained from all sampling sites were contaminated with one or more pesticide residues. Chloroflurenol-methyl was the most predominantly detected OPPs residue in all crop samples obtained from different sampling sites, with a maximum concentration of 0.402 mg kg−1 in potato samples obtained from the Gurafarda site and a minimum value of 0.049 mg kg−1 in onion samples obtained from the South Bench site. Dibutyl chlorendate was the predominant OCPs in all samples, with the minimum value of 0.498 mg kg−1, which was detected in tomato samples collected from the Jamo site, and the maximum concentration of 1.003 mg kg−1 detected in pineapple samples obtained from the North Bench site. Dimethoate concentrations in tomato samples (0.045–0.084 mg kg−1) were above the maximum residue limits (MRLs) established by the European Union (EU) guidelines (0.01 mg kg−1) but were below the MRLs established by Codex Alimentarius Commission (CAC) guidelines (0.5 mg kg−1). Relatively high residue concentrations of dibutyl chlorendate and chloroflurenol-methyl were detected in all the samples obtained from all sampling sites. There is widespread use of pesticides for agriculture by the producers in the study area and there is a need for the regular monitoring of pesticide residues.