Potentiometric multisensory system based on perfluorosulfonic acid membranes and carbon nanotubes for sulfacetamide determination in pharmaceuticals

Abstract

Abstract Hybrid materials based on perfluorinated sulfonic acid (PFSA) Nafion®-type membranes with homogeneous and with a gradient distribution of multiwalled carbon nanotubes (CNTs) along the sample were obtained. The studies of water uptake, ionic conductivity, and diffusion permeability of the materials were performed. Hybrid membranes were used to create potentiometric Donnan potential (DP) sensors. The influence of the CNTs concentration on the performance of the sensors in aqueous solutions containing sulfacetamide anions and alkali metal cations was studied. The dependences of the cross-sensitivity of DP sensors to anions and cations on the diffusion permeability of the hybrid membranes were established. A potentiometric multisensory system was developed for the simultaneous determination of sulfacetamide anions and potassium (or sodium) cations at concentrations range from 1.0·10−4 to 1.0·10−2 M and рН from 5 to 8. The advantages of the system are the following: the response time of the system is less than 1 min, the analysis does not require sample preparation, and the characteristics of the sensors persist for at least 1 year. An array of cross-sensitive DP-sensors based on PFSA Nafion®-type membranes, containing 1.0 and 1.5 wt% CNTs, was used to determine the active component in the drug “Sulfacyl sodium (Albucide)” (eye drops). The accuracy of the determination is 94–95%.