Abstract

: Coumaphos is an organophosphorus compound used as insecticide and frequently used by
beekeepers for the management of parasitic mites. The most important metabolite, chlorferron (CFN),
has been identified in biological samples and foodstuff. The need to quickly identify the presence of
typical metabolites, as an indication of interaction with coumaphos has driven the need to produce a
highly sensitive electrochemical method for chlorferron analysis, based on molecularly imprinting
polymers (MIP) technology. It showed irreversible behaviour with mixed diffusion/adsorption�controlled reactions at the electrode surface. A monoelectronic mechanism of reaction for oxidation
has also been suggested. The linear range observed was from 0.158 to 75 µM. Median precision in
terms of %RSD around 3% was also observed. For DPV, the limit of detection (LOD) and the limit
of quantitation (LOQ) for the CFN-MIP were 0.158 µM and 0.48 µM, respectively. The obtained
median % recovery was around 98%. The results were also validated to reference values obtained
using GC-MS. Urine and human synthetic plasma spiked with CFN were used to demonstrate the
usability of the method in biological samples, showing the potential for biomonitoring. The developed
imprinted sensor showed maximum signal change less than 16.8% when related metabolites or
pesticide were added to the mix, suggesting high selectivity of the MIP sensor toward CFN molecules.
The results from in vitro metabolism of CMP analysed also demonstrates the potential for detection
and quantification of CFN in environmental samples. The newly developed CFN-MIP sensor offers
similar LoDs than chromatographic methods with shorter analysis time.