Voltammetric Determination of Carprofen

Abstract

Background: The aim of this work was to develop a simple voltammetric method for quantitative determination of the veterinary drug carprofen. To the best of our knowledge there is no literature data on the voltammetric behavior and quantification of carprofen. Methods: Cyclic voltammetry (CV) on a glassy carbon electrode was employed to study the voltammetric behavior of carprofen by investigating the influence of the scan rate and of the supporting electrolyte pH. A differential pulse voltammetric (DPV) method for carprofen quantification was optimized with respect to supporting electrolyte and instrumental parameters. The applicability of the developed method was tested on carprofen’s determination from pharmaceuticals. An HPLC method was used for comparison. Results: CV emphasized that carprofen presents an oxidation wave corresponding to an irreversible and pH –dependent electrode process involving an equal number (n) of protons and electrons (n=1). The linear range and detection limit of the developed DPV method were 7.17×10-7–8.98×10-5 M and 2.62×10-7 M carprofen, respectively. Statistical tests (F, t, Cochran) confirmed that the results obtained by DPV are well correlated with those of the HPLC reference method. Conclusion: This paper reports for the first time a CV study of carprofen and an optimized DPV method for its rapid determination. The method has a linear range of over two orders of magnitude and a submicromolar limit of detection. Statistical analysis proved that the results of carprofen determination by DPV and HPLC from injections were comparable and reliable being in good agreement with the manufacturer claimed amount. Keywords: Carprofen, glassy carbon electrode, pharmaceuticals, voltammetry, differential pulse voltammetric (DPV), HPLC.