Determination of organochlorine and organophosphorus pesticide residues in tomato, potato, and pineapple samples of selected farmlands in southwest Ethiopia

Abstract

ABSTRACT. In this study, the residual concentrations of some organophosphate and organochlorine pesticides were determined in tomato, potato, and pineapple samples from selected farmlands of Jimma and Kefa Zones, Southwest of Ethiopia. The QuEChERS procedure, AOAC-2007, was used for extraction of the pesticides from the samples prior to their determinations by a gas GC-ECD. Pesticides including dichlorodiphenyltrichloroethane, endrin, and dieldrin were not detected in all studied samples. Dimethoate was detected only in Mana and Saka Buyo Qacama tomato samples. Likewise, malathion was detected only in the Saka Buyo Qacama tomato sample. The residual concentrations of most of the studied pesticides were below their MRLs set in EU guideline. However, the recorded residual concentrations of dibutyl chlorendate and chloroflurenol-methyl pesticides were above the EU general default MRL. The percent recoveries studied by spiking known concentrations of the analytes ranged from 71.22–121.56%. However, the recoveries of chloroflurenol-methyl and chlorpyrifos in the potato sample were 65.65 and 67.90%, respectively. One-way ANOVA results (p ≤ 0.05) indicated the presence of significant variations in the concentrations of the detected pesticides among the sampling sites. Generally, the findings showed that regular monitoring of pesticide residues in agricultural products of the area is needed.

KEY WORDS: Organophosphates and organochlorines pesticides, QuEChERS, Tomato, potato, and pineapple samples, GC-ECD

Bull. Chem. Soc. Ethiop. 2023, 37(1), 23-33.                                                            

DOI: https://dx.doi.org/10.4314/bcse.v37i1.3