Asian Australas. J. Food Saf. Secur. 2021, 5 (2), 63-70; https://doi.org/10.3329/aajfss.v5i2.56957 Asian-Australasian Journal of Food Safety and Security ISSN 2523-1073 (Print) 2523-2983(Online) https://www.ebupress.com/journal/aajfss/ Article Monitoring of pesticide residues in vegetables collected from retail markets of Dhaka district of Bangladesh using QuEChERS Extraction and Gas Chromatography Rakibul Hasan 1 , Md. Mahadi Alam 1 , S M Mizanur Rahman 1 , Deeder Sultana 2 and Mohammad Dalower Hossain Prodhan 3* 1 Department of Entomology, Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh 2 Planning & Evaluation Wing, Bangladesh Agricultural Research Institute, Gazipur-1701, Bangladesh 3 Pesticide Analytical Laboratory, Pesticide Research & Environmental Toxicology Section, Entomology Division, Bangladesh Agricultural Research Institute, Gazipur-1701, Bangladesh * Corresponding author: Mohammad Dalower Hossain Prodhan, Pesticide Analytical Laboratory, Pesticide Research & Environmental Toxicology Section, Entomology Division, Bangladesh Agricultural Research Institute, Gazipur-1701, Bangladesh. Phone: +8801819849657; E-mail: dalowerag@yahoo.com; mdhprodhan@gmail.com Received: 27 August 2021/Accepted: 21 November 2021/ Published: 30 November 2021 Copyright © 2021 Rakibul Hasan et al. This is an open access article distributed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract: The present study was aimed to detect and quantify major organophosphorus pesticide residues in cauliflower and cucumber collected from different retail markets of Dhaka city, Bangladesh. In this study, a total of 50 vegetable samples (30 samples of cauliflower and 20 samples of cucumber) were analyzed using Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) extraction technique and Gas Chromatography coupled with Flame Thermionic Detector (GC-FTD). Among the 30 analyzed samples of cauliflower, 5 samples (16.7% of the total number of samples) contained residues of chlorpyrifos, quinalphos, acephate and dimethoate, where 4 samples contained multiple pesticide residues. All the contaminated samples of cauliflower contained residues above the EU-MRL. On the other hand, among the 20 analyzed samples of cucumber, only 2 samples (10% of the total number of samples) contained residues of quinalphos and chlorpyrifos at a level being below the EU-MRL. This study reflects the overall scenario of pesticide residues remain in cauliflower and cucumber purchased from different local markets of Dhaka city, which will help the consumer to be aware of their health and safety. The findings derived from this study reveals the public health concern due to the potential of pesticide toxicity in vegetables for the consumers. Therefore, continuous monitoring on the use of pesticides in vegetables should be strengthened. Keywords: organophosphorus pesticide residues; vegetables; QuEChERS extraction; gas chromatography 1. Introduction Vegetables are commonly used to fulfill the balance diet requirement as they are a vital source of vitamins and fiber. It makes up a major portion of the diet of humans in many parts of the world and play a significant role in human nutrition, especially as sources of vitamins (C, A, B1, B6, B9, E), minerals, dietary fiber and phytochemicals (Wargovich, 2000; Dias and Ryder, 2011). The cauliflower and cucumber are the two important vegetables grown commercially in Bangladesh. Cauliflower is low in fat, high in dietary fiber, contains water and vitamin C, possessing a very high nutritional density. The warm and humid climatic condition of the