Analysis of multiple pesticide residues in market samples of okra and associated dietary risk assessment for consumers.

Abstract

European Union Reference Laboratory method for Fruits and Vegetables (EURL-FV-2010-M1) for the quantification of pesticide residues was verified for the determination of multiple pesticide 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 0.002mg/kg for carbofuran to 0.5mg/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 1.40 × 10-6 and 1.78 × 10-4mg/kg of body weight, chronic exposure risk (%ADI) ranged from 0.0073 to 1.8%, and acute exposure risk (%ARfD) ranged from 0.01 to 24.20%. The results exhibited insignificant risk from chronic exposure and minor to medium level of risk from acute exposure of these pesticides to human health.