Abstract
A simple and effective extraction method based on matrix solid-phase dispersion was developed to determine dimethoate, methyl-parathion, malathion, tebuconazole and cypermethrin in tomato using gas chromatography-mass spectrometry and selected ion monitoring (GC-MS, SIM). Different parameters of the method were evaluated, such as type of solid phase (C18, alumina, silica-gel and Florisil), the amount of solid phase and eluent [dichloromethane, ethyl acetate, n-hexane and n-hexane:ethyl acetate (1:1 and 1:3, v/v)]. The best results were obtained using 2.0 g of tomato, 0.5 g of alumina as dispersant sorbent, 0.5 g of Florisil as clean-up sorbent and dichloromethane as eluting solvent. The method was validated by fortified tomato samples at different concentration levels (0.05 to 4.0 mg kg-1). Average recoveries (7 replicates) ranged from 77% to 100% with relative standard deviation between 3.7% and 12.9%. Detection and quantification limits ranged from 0.01 to 0.02 mg kg-1 and 0.03 to 0.06 mg kg-1 for the whole fruit of tomato, respectively. The proposed method was applied to analyze of these compounds in commercial tomato samples and residues of methyl-parathion, dimethoate and malathion were detected on the tomato samples at concentrations below the maximum residue levels (MRLs) established by Brazilian legislation and Codex Alimentarius.
Highlights
The tomato fruit (Lycopersicon esculentum) is one of the most important components of the human diet in different countries, where it is consumed in its raw form, home-cooked or processed as juice or paste
The matrix effect was evaluated by comparing the detector response with regards to the pesticide standards prepared in dichloromethane to pesticide standards prepared in tomato extract
When standards were prepared by spiking blank tomato samples with known amounts of pesticides, higher peak areas were obtained from the same pesticide concentrations
Summary
The tomato fruit (Lycopersicon esculentum) is one of the most important components of the human diet in different countries, where it is consumed in its raw form, home-cooked or processed as juice or paste. Development of MSPD Method for the Determination of Pesticide Residues belong to the classes of organophosphorus, pyrethroids, triazoles and are mainly malathion, methyl-parathion, dimethoate, cypermethrin and tebuconazole.[2] With regards to methyl-parathion it is important to notice that it was formerly used, but it has recently been discontinued in compliance to the Brazilian legislation. After their application, pesticide residues may remain in this crop and constitute a health risk because of their toxicity. Studies have suggested that malathion and dimethoate have been identified as potential endocrine disruptors.[3,4,5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
