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

Multisensory Systems Based on Perfluorosulfonic Acid Membranes Modified with Polyaniline and PEDOT for Multicomponent Analysis of Sulfacetamide Pharmaceuticals

“…The DP-sensor sensitivity to sulfacetamide anions is higher and changes a lot depending on the dopant nature, concentration of monomer or oxidant and membrane preparation method (Figures 6 and 7). A high sensitivity of the DP-sensors to the organic analytes in anion and zwitterion forms for the composites based on Nafion-type membranes has been described previously [40,41]. Since membranes are not absolutely selective, transport of organic anions and molecules into a cation-exchange membrane is possible.…”

“…Membranes in the K + -form were used in the DP-sensors. The cell scheme for the response evaluation of DP-sensor systems based on membranes with different compositions is thoroughly described elsewhere [40,41]). The distance between boundaries of an ion-exchange membrane with a reference and test solutions corresponds to the membrane length (6 cm) and not to its thickness as in traditional potentiometric sensors with inner filling.…”

“…Anion sorption can be even more effective than that of uncharged molecules despite the Donnan exclusion. A facilitated transport of organic anions into the membrane is observed if other cations (Na + ) than those of initial ionic membrane form (K + ) are presented in the external solution [41]. In this case, anion transport into the membrane occurs via hydrogen bonds with hydration shells of cations involved in ion exchange.…”

“…It allowed varying the concentration and nature of reactive centers in a membrane as well as its microstructure and conductivity that affect the sorption efficiency of analytes by ion-exchange and non-exchange mechanisms. The prospects of investigation of composites based on perfluorosulfonic acid membranes are associated with the possibility of varying potentiometric sensitivity to organic analytes due to nonspecific ion-ionic, ion-dipole, and hydrophobic interactions with membrane [40,41].…”

MF-4SC Membranes Modified by Polyaniline for Potentiometric Determination of Saccharin and Sodium Ions in Aqueous Solutions

“…This becomes possible if the analytes are organic co-ions or uncharged particles capable of the protonation in the membrane phase, formation of hydrogen bonds, or electrostatic interaction with the functional groups of the membrane. Since the analyte enters the membrane through non-exchange sorption, an increase in its concentration in the pores can also be facilitated by hydrophobic interactions with dopant fragments, as exemplified by membranes containing carbon nanotubes (CNTs) [15] and poly(3,4-ethylenedioxythiophene) (PEDOT) [16]. In this work, for the joint determination of sodium and saccharin ions, composite membranes MF-4SC modified with polyaniline (PANI) were proposed.…”