Analysis of Multiple Pesticides Residues in Market Samples of Okra and Associated Dietary Risk Assessment for Consumers

Abstract

European Union Reference Laboratory method for Fruits and Vegetable (EURL-FV-2010-M1) for the quantification of pesticide residues was verified for the determination of multiple pesticides residues in okra. The targeted pesticides were extracted using acetonitrile with citrate buffer salts followed by cleanup with primary secondary amine (PSA) and analyzed on LC-MS/MS. The recoveries for all the targeted pesticides were within an acceptable range of 70.1 - 116.6% and precision in terms of RSD was 0.3 - 18.1%, respectively. The limit of quantification ranged from 0.002 mg/kg for carbofuran to 0.5 mg/kg for α-cypermethrin. The status of pesticide residues in okra (n= 21) available to consumers in the main markets of Pakistan has been determined by using this verified method. Sixty-two percent of the tested samples were contaminated out of which three samples were non-compliant with European Union Maximum residue limits (EU-MRL). The pesticides violating the EU-MRL were bifenthrin, thiamethoxam, and triazophos. For all the detected pesticides, estimated daily intake (EDI) ranged between 7.39×10−6 and 1.78×10−4 mg/kg of body weight while the values of Health Index (HI) fluctuated between 8.9×10−5 and 1.8×10−2. Although, residues of some pesticides were reported to be non-compliant with EU-MRLs, yet the risk posed by these pesticides to human health was insignificant.