Simultaneous Determination of Three Trace Organophosphorus Pesticide Residues in Vegetables Using Molecularly Imprinted Solid-Phase Extraction Coupled with High-Performance Liquid Chromatography

Abstract

In this study, a molecularly imprinted polymer that can selectively recognize dimethoate, isocarbophos, and methyl parathion was synthesized. Using this compound as sorbent, a new method for simultaneous determination of the three organophosphorus pesticides by molecularly imprinted solid-phase extraction coupled with high-performance liquid chromatography was established. The factors affecting the preconcentration and sensitivity were studied in detail. Under optimal conditions, the limits of detection of this method for dimethoate, isocarbophos, and methyl parathion were 19.78, 8.73, and 17.41 μg/kg, respectively. The relative standard deviation for five replicates of 0.01 mg/L-mixed solutions was in the range of 1.8-4.2 %. Cucumber sample spiked with the three organophosphorus pesticides at levels of 0.125 and 0.250 μg/g were examined using this method, good recoveries were obtained ranging from 82.5 to 95.6 %. Moreover, this method was also successfully used for the detection of the three organophosphorus pesticides in cauliflower sample.

Molecularly imprinted polymers for the determination of organophosphorus pesticides in complex samples

“…As mentioned by some authors, the selection of the monomer(s) and the template/monomer(s) ratio can be carried out by studying the changes in UV spectra of the template when adding increasing concentration of the monomer in the solvent selected for the synthesis [67,69,77]. Other spectroscopic methods were used such as NMR to highlight the presence of hydrogen bonds between the template and MAA [39,67,69,72,73] and FT-IR to highlight the interactions between OPP and OH-group of MAA [39,46,55,61,70,76,80,91,97,98,102]. This method was also used to control the template removal by comparing MIP spectrum before and after its washing [64,93,99], this control being most of the time ensured by analyzing the template amount in the washing solution by UV detection or by chromatographic analysis.…”

“…three molecules that comprise an aromatic ring with one or two linked nitrogen atoms [97]. Some authors reported the ability of the MIP to extract up to six OPPs with high recovery rates but the NIP was not used in parallel to the MIP when optimizing the SPE procedure [42,50,61,68,76,80]. In these conditions, the retention was certainly favored by the solvent selected as percolating medium but the real selectivity, believed to being brought by the cavities of the MIP, was not really proven.…”

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.…”

“…This comparison between MIP and NIP achieved in spiked pure media allows to put in evidence the presence of cavities in the MIP and is also useful to optimize the extraction procedure that must give rise to high extraction recovery on the MIP and low one on the NIP [8]. Except for one reported work [21], the conditions of extraction finalized in pure media were applied to real samples [11,[17][18][19][20][22][23][24][25][26][27]38] without a control of the selectivity by using the NIP or without reoptimization of the extraction conditions to circumvent matrix effects as already reported [8]. These matrix effects were well illustrated by Sanagi et al who reported recoveries obtained in pure media and in real samples after applying the same extraction procedure on MIP and on NIP [21].…”

Optimization of Procedure of Separate Biosensor Detection of Aflatoxins and Pesticides

“…До традиційних методів визначення афлатоксинів відносять тонкошарову хроматографію [6], високоефективну рідинну хроматографію (ВЕРХ) [7], різні поєднання рідинної хроматографії з мас-спектрометрією [8] та імуноферментний аналіз [9]. Для визначення фосфороорганічних пестицидів використовують хроматографічні методи [10][11][12][13], включаючи ВЕРХ [14,15] та газову хроматографію [16]. Методи, що дозволяють визначати важкі метали (наприклад, кадмій, ртуть, свинець, миш'як, олово, селен, сурму, мідь, нікель, хром, телур, талій), включають атомно-абсорбційну або емісійну спектроскопію, рентгенівську флуоресцентну спектрометрію, хроматографічні або електрохімічні методи аналізу [17][18][19].…”