Development of Solid-Phase Extraction Using Molecularly Imprinted Polymer for the Analysis of Organophosphorus Pesticides-(Chlorpyrifos) in Aqueous Solution

Binsalom A,Zourob M,Campbell K,Chianella I

doi:10.4172/2157-7064.1000340

Abstract

A new and selective sorbent for molecularly imprinted solid-phase extraction (MISPE) was prepared to extract chlorpyrifos (CPF) residue from solutions. The extracted analyte was analyzed by high performance liquid chromotography (HPLC) coupled with photodiode array detection. To synthesize the molecularly imprinted polymers, four different pyrogens (acetonitrile, toluene, dichloromethane and chloroform) were initially studied. CPF was used as the template molecule, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the crosslinker. Thermo-polymerization method was used to produce bulk polymers. In order to determine the medium that enhances the best molecular recognition, the adsorption study of CPF to the MIPs was investigated. Both organic solvents and water were utilized as media. The acetonitrile solvent was finally selected as pyrogen for the synthesis of the polymers and water was chosen as the medium for loading the analytes into the polymers. The selectivity of the MISPE method for CPF and other pesticides in aqueous solution was also assessed.

Highlights

Sample preparation plays a key role for a fruitful and accurate analysis of pesticide residues in food [1]
Imprinted polymers can be prepared in many formats, with the bulk format being the most straightforward, simple and suitable to produce an Solid Phase Extraction (SPE) sorbent
methacrylic acid (MAA) was chosen here as it is a widely used functional monomer which can behave both as a hydrogen bond donor and acceptor if it is used with a suitable pyrogen [14]

Summary

Introduction

Sample preparation plays a key role for a fruitful and accurate analysis of pesticide residues in food [1]. Solid Phase Extraction (SPE) is amongst the most common techniques used to extract, purify and concentrate analytes. This technique relies on the repartition of the analyte between a solid phase (usually a polymeric sorbent such as C18 packed in a tube) and a mobile phase namely the solvent used for loading, washing and recovering the analyte. Imprinted polymers (MIPs), which are synthetic polymeric materials that contain receptor sites able to recognize a target compound or similar structures [2], have shown to be an excellent sorbent for molecularly imprinted solid-phase extraction (MISPE). MIPs are produced by a polymerization process following a self-assembly step between the target analyte and functional monomers.

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Results

Conclusion