Determination of benzimidazoles and ciprofloxacin in milk by dispersive microextraction with electrochemical detection based on carbon nanotubes modified with electropolymerized L-DOPA

ARSENIO MUÑOZ DE LA PEÑA; CARLA M. TEGLIA; FABIANA A. GUTIERREZ; HÉCTOR C. GOICOECHEA

Amsterdam

Conferencia; ISEAC 41; 2023

The presence of active principles for veterinary use in food is a reality that leads to the generation of public policies tending to define the maximum residue limits. In this scenario, it is extremely important to have simple detection and quantification methods for multi-analyte analysis. Within food matrices, due to its components, milk is a highly complex sample, so the pretreatment steps for subsequent detection with complex methods, such as chromatography, are complicated. In the present work, a dispersive microextraction method was developed for the extraction of albendazole (ABZ), febendazole (FBZ), thiabendazole (TBZ) and ciprofloxacin (CIP), making use of the effervescent capacity of sodium carbonate to achieve the best dispersion and extraction of the analytes of interest in the extracting solvent. In parallel, a sensor platform based on carbon nanotubes modified with electropolymerized L-- 3,4-Dihydroxy-phenylalanine (L-DOPA) was developed to generate a melanic polymer. In general, conjugated compounds having polyaromatic rings and functional groups bind to the sp2 lattice of graphene sheets of the nanotube by - stacking, and the functional moieties stabilize the sp2 sheets in the solvent and provide new functionalities to the nanomaterial.Therefore, the study of the interactions between melanic polymers with different substrates has been implemented over the years for various purposes, including surface functionalization. Finally, the combination between the microextraction system and the electrochemical detection allowed, thanks to the preconcentration factor, to obtain good detection limits. The method was validated obtaining good results. The complete system was tested with samples from different sources, in order to determine the presence of the compounds in commercial milk samples.