Preparation of malathion MIP-SPE and its application in environmental analysis

Abstract

Malathion is an organophosphorous insecticide for controlling insects on fruits and vegetables, miscellaneous household insects, and animal parasites. It is important to develop highly efficient and selective pre-treatment method for analyzing malathion residues in environment and samples from agricultural products based on the molecularly imprinted polymers (MIPs). In this study, we developed a tailor-made MIP method with highly specific recognization to the template. The MIPs were prepared using malathion as a template, methacrylic acid (MAA) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a crosslinker, azodiisobutyronitrile (AIBN) as an initiator, and the acetonitrile-chloroform (1:1, v/v) as a porogen. The molecular recognization mechanism of malathion and MAA was evaluated by molecular simulation, ultraviolet spectrometry (UV), and (1)H-nuclear magnetic resonance ((1)H-NMR). MAA interacted specifically with malathion by hydrogen bond with a ratio of 2:1. The MIPs exhibit a high affinity, recognition specificity, and efficient adsorption performance for malathion. The Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), surface area and porosimeter analyzer, thermogravimetric/differential thermal analyzer (TG/DTA) were used to characterize the properties of MIP. The malathion residues in soil, tap water, and cabbage were cleaned up by MIP-SPE, detected quantitatively using GC-FPD, and confirmed by GC-MS/MS. The limits of tap water, soil, and cabbage were confined to 0.001 mg L(-1), 0.004 and 0.004 mg kg(-1), respectively. The spiked recoveries of malathion were 96.06-111.49% (with RSD being 5.7-9.2%), 98.13-103.83% (RSD, 3.5-8.7%), and 84.94-93.69% (RSD, 4.7-5.8%) for tap water, soil, and cabbage samples, respectively. Thus, the method developed here can be used effectively in assessing malathion residues in multiple environmental samples. The aim of the study was to provide an efficient, selective, and accurate method for analyzing malathion at trace levels in multiple media.

Synthesis and application of molecularly imprinted polymers for the selective extraction of organophosphorus pesticides from vegetable oils

“…The development of MIPs for the extraction of OPs has been largely reported these last years. MIPs were prepared as particles to be used in cartridges between two frits as SPE sorbent [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] or as dispersive sorbent for dSPE [27][28][29][30][31] and for matrix solid-phase dispersion (MSPD) [32][33][34] or as a thin film in solid-phase microextraction (SPME) [35][36][37] or in stir bar sorption extraction (SBSE) [38]. They were applied to the selective extraction of OPs from vegetable extracts (cucumber, lettuce, apple, pear…) and environmental samples such as waters and soil extracts.…”

“…The effect of the template was studied only once for the development of an MIP for dimethoate and its metabolite omethoate showing that the metabolite was better adapted for the trapping of both molecules [19]. A few studies described the synthesis of an MIP by varying the nature of the monomer [11,19,28,30,31] and/or the porogen [11,25,30,31] or the template/monomer ratio [24]. In some studies, the choice of the monomer for a given template resulted from studies by molecular modeling and computational design [17,19,23].…”

Molecular imprinting: perspectives and applications

“…Based on the above point, some kinds of solvents are widely used, such as dichloromethane, acetonitrile, methanol, acetone, and water. [324][325][326][327][328] Eluting the target analytes from MIP sorbents using a specific solvent is the last step of MISPE. The eluting solvent should be strong enough to release the analytes from the binding sites.…”

Cyclosporine A/porous quaternized chitosan microspheres as a novel pulmonary drug delivery system

“…Blank microparticles were labelled MS D (Table 1). ABC [17], poly(propylene glycol)-block-poly(ethylene glycol)-block-poly (propylene glycol) (F68) [27], polyethylene glycol (PEG, Mn ¼ 20,000) [28], chloroform (Chl) [29], and polystyrene (PS) MS [30] were selected as porogens in this study. ABC was utilized as an effervescent porogen in the formulations of MS E, MS F, MS G, MS H, MS I, MS J, MS K, MS L, and MS M. The morphological characteristics of MS evidently differed when the formulations were varied.…”