Molecularly imprinted polymer solid-phase extraction coupled to square wave voltammetry at carbon fibre microelectrodes for the determination of fenbendazole in beef liver

Anal Bioanal Chem. 2007 May;388(1):227-34. doi: 10.1007/s00216-007-1233-z. Epub 2007 Mar 13.

Abstract

A molecularly imprinted polymer was developed and used for solid-phase extraction (MISPE) of the antihelmintic fenbendazole in beef liver samples. Detection of the analyte was accomplished using square wave voltammetry (SWV) at a cylindrical carbon fibre microelectrode (CFME). A mixture of MeOH/HAc (9:1) was employed both as eluent in the MISPE system and as working medium for electrochemical detection of fenbendazole. The limit of detection was 1.9x10(-7) mol L-1 (57 microg L-1), which was appropriate for the determination of fenbendazole at the maximum residue level permitted by the European Commission (500 microg kg-1 in liver). Given that the SW voltammetric analysis could not be directly performed in the sample extract as a consequence of interference from some sample components, a sample clean-up with a MIP for selectively retaining fenbendazole was performed. The MIP was synthesized using a 1:8:22 template/methacrylic acid/ethylene glycol dimethacrylate ratio. A Britton-Robinson Buffer of pH 9.0 was selected for retaining fenbendazole in the MIP cartridges, and an eluent volume of 5.0 mL at a flow rate of 2.0 mL min-1 was chosen in the elution step. Cross-reactivity with the MIP was observed for other benzimidazoles. The synthesized MIP exhibited a good selectivity for benzimidazoles with respect to other veterinary drugs. The applicability of the MISPE-SWV method was tested with beef liver samples, spiked with fenbendazole at 5,000 and 500 microg kg-1. Results obtained for ten different liver samples yielded mean recoveries of (95+/-12)% and (96+/-11)% for the upper and lower concentration level, respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antinematodal Agents / analysis*
  • Carbon / chemistry*
  • Cattle
  • Electrochemistry
  • Fenbendazole / analysis*
  • Food Contamination / analysis
  • Liver / chemistry*
  • Meat Products / analysis
  • Meat Products / standards
  • Microelectrodes
  • Polymers / chemistry*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Solid Phase Extraction*

Substances

  • Antinematodal Agents
  • Polymers
  • Fenbendazole
  • Carbon