Development of the New Sensor Based on Functionalized Carbon Nanomaterials for Promethazine Hydrochloride Determination

Abstract

Promethazine hydrochloride (PM) is a widely used drug so its determination is important. Solid-contact potentiometric sensors could be an appropriate solution for that purpose due to their analytical properties. The aim of this research was to develop solid-contact sensor for potentiometric determination of PM. It had a liquid membrane containing hybrid sensing material based on functionalized carbon nanomaterials and PM ions. The membrane composition for the new PM sensor was optimized by varying different membrane plasticizers and the content of the sensing material. The plasticizer was selected based on calculations of Hansen solubility parameters (HSP) and experimental data. The best analytical performances were obtained using a sensor with 2-nitrophenyl phenyl ether (NPPE) as the plasticizer and 4% of the sensing material. It had a Nernstian slope (59.4 mV/decade of activity), a wide working range (6.2 × 10−7 M–5.0 × 10−3 M), a low limit of detection (1.5 × 10−7 M), fast response time (6 s), low signal drift (−1.2 mV/hour), and good selectivity. The working pH range of the sensor was between 2 and 7. The new PM sensor was successfully used for accurate PM determination in a pure aqueous PM solution and pharmaceutical products. For that purpose, the Gran method and potentiometric titration were used.

Design Criteria for Nanostructured Carbon Materials as Solid Contacts for Ion‐Selective Sensors

“…Whereas access to a high surface area may be limited in some solids with very small pores, most of the surface should be accessible to ion-ionophore complexes, hydrophobic ionic sites, and other ISM components in the case of nonporous, nanostructured, high-surface area carbon materials. These include single-walled carbon nanotubes (SWCNTs), [77][78][79][80] multi-walled carbon nanotubes (MWCNTs), [81][82][83][84][85][86][87][88][89][90] nanohorns (bud-like structures derived from SWCNTs), [91] buckyballs, [92][93][94] and certain types of carbon black. [95][96][97] Certain MWCNTs with thin walls can also contain internal porosity, although infiltration of ionophore molecules may be diffusion-limited in relatively long (micrometer length) but narrow (e.g., 40 nm) channels.…”