Electrochemical Study of Different Sensors for Simple and fast Quantification of Ciprofloxacin in Pharmaceutical Formulations and Bovine Milk

In this paper, bare glassy carbon electrode (GCE), multi-walled carbon nanotubes (MWCNT/GCE) and reduced graphene oxide (RGO/GCE) were to verify the ciprofloxacin oxidation process. The RGO/GCE electrode provided a 9-fold increase in the analytical signal and a potential displacement of 50 mV. A method using flow injection analysis with amperometric detection has been developed for simple and fast detection of ciprofloxacin in pharmaceutical formulations and bovine milk. The method presented adequate analytical characteristics, limit of detection (LOD<0.1 mu mol L-1), simple sample treatment (only dilution supporting electrolyte), analytical frequency (110 analyzes per hour), satisfactory linear range (1-100 mu mol L-1) and good precision (RSD<3%). The method was applied in six samples with satisfactory accuracy (recovery values in the range of 101 to 113 %). The ciprofloxacin contents were in agreement with the values provided by the drug labels, while the levels in the milk samples were below the LOD. The results obtained for both applications were statistically equivalent to the results obtained by liquid chromatography, at a 95 % confidence level.