A validated potentiometric method for determination of alfuzosin hydrochloride in pharmaceutical and biological fluid samples

Abstract

Recently, graphene nanosheet has attracted the most attention for the potential applications in various electrochemical sensing fields to biomedical diagnosis and therapy due to its large theoretical specific surface area, unique physical and electrical properties. In this paper, a newly sensitive and selective modified carbon paste electrodes (MCPEs) were developed for the determination of alfuzosin hydrochloride (ALF.HCl) in pharmaceutical preparation and biological fluid samples. The paste of these sensors was prepared by mixing alfuzosin phosphomolybdate (ALF-PMA) and alfuzosin tetraphenylborate (ALF-TPB) ion pairs as recognition reagents with different supporting matrices including graphite powder alone or different ratios of graphite to graphene powders and plasticizer of a relatively high dielectric constant. The sensor prepared based on graphite alone as a supporting matrix gave Nernstian slope values of 56.7 ± 0.75 and 51.1 ± 1.11 mV decade−1 for electrode modified with ALF-PMA and ALF-TPB ion pairs, respectively, in the concentration range from 1.0 × 10−5 to 1.0 × 10−2 mol L−1 at 25 °C, and the response of the electrode was found to be independent on pH in the range of 2.0–5.0. The Nernstian slope for ALF-TPB modified carbon paste electrode was improved to be 55.8 ± 1.07 mV decade−1 upon mixing graphene with graphite in the paste and showed pH independence in the range of 2.0–6.0. The proposed sensors were successfully applied for the determination of ALF.HCl in pure, biological fluid samples and pharmaceutical preparation using the direct potentiometric and standard addition methods. Finally, the results obtained using the proposed sensors were compared with those from the official method.