Electropolymerized MIP with MWCNTs on Stir Bar Using Multivariate Optimization for Tetradifon Detection in Date

Abstract

Background: Multi-walled carbon nanotubes (MWCNT) adjunct to molecularly imprinted polymers (MIP) have advantages of the large surface area of nanoparticles and selectivity of MIPs for selective extraction of tetradifon as a widely used pesticide in date palm. Objectives: The main aims were the use of experimental design, electrochemical synthesis and ultra-high performance liquid chromatography (UHPLC) to develop a simple, reliable and precise pesticide residue analysis method as an important aspect of food and drug quality control for the determination of tetradifon in date palms. Methods: An MIP in the presence of MWCNT was synthesized by cyclic voltammetric technique on a steel rod to produce a composite of MIP-MWCNTs for stir bar extraction of tetradifon residue in date samples. The experimental design was used to optimize MIP-MWCNT composite synthesis through the screening of eight variables. The composite was characterized by scanning electron microscopy (SEM). Tetradifon was determined in extracted samples by UHPLC under optimum conditions. Results: A very thin film was made by MIP-MWCNT coated on a steel rod which was repeatable and had good adhesion and persistence. The detection limit (LOD) and the quanti-fication limit (LOQ) of the method were measured as 16 and 49 ng/ml, respectively. Average recovery of tetradifon at the two spiked levels was observed to be as low as 86.5% to 90.7% (RSD from 0.79% to 1.04%). Conclusion: The low cost, high selectivity, good reproducibility, acceptable intra and inter day precision and accuracy developed method were successfully applied to determine tetradifon residue in date samples purchased from a local market.