Molecularly Imprinted Polymers with Dual Template and Bifunctional Monomers for Selective and Simultaneous Solid-Phase Extraction and Gas Chromatographic Determination of Four Plant Growth Regulators in Plant-Derived Tissues and Foods

Abstract

A highly selective and sensitive molecularly imprinted polymer (MIP)-based solid-phase extraction (SPE) combined with gas chromatographic (GC) detection method was developed for the simultaneous isolation and determination of four plant growth regulators (PGRs) including indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), 1-naphthaleneacetic acid (NAA), and 2,4-dichlorophenoxyacetic acid (2,4-D) in plant tissues, fruits, and vegetables. The MIP composites, synthesized by application of dual template molecules (IAA and 2,4-D) and bifunctional monomers β-cyclodextrin (β-CD) and methacrylic acid (MAA), were characterized by FTIR, BET, XRD, SEM, and TGA techniques. The effects of the amount of adsorbent, sample pH, and eluent solvents on the SPE performance were investigated. Under the optimal SPE condition, the β-CD/MAA-MIPs exhibited higher selective capability and greater adsorption capacity toward target PGRs when compared with commercial SPE adsorbents, single template, and functional monomer MIPs. In addition, the stability and reusability studies demonstrated that the synthesized β-CD/MAA-MIPs were capable for reutilization with stable performance in sample pretreatment process. Finally, the proposed β-CD/MAA-MIPs-SPE-GC technique was successfully applied to analyze the interested PGRs in different plant tissues, fruits, and vegetable samples.