Electrochemical screening of selected β-blockers at a polarized liquid-liquid interface

This paper describes the electrochemical behavior of five beta-blockers at the polarized liquid-liquid interface formed between aqueous solution (sodium chloride solution or Britton-Robinson buffers) and bis(triphenylphosphoranylidene)ammonium tetrakis(4-chlorophenyl)borate (BTPPATPBCl) dissolved in 1,2-dichloroethane (the organic phase). All measurements reported in this work were conducted using cyclic voltammetry (CV). The effects of the concentration of analytes, the pH of the aqueous phase, and applied electrochemical parameters on the analytical performance of the studied system are studied and discussed. The linear dynamic ranges (LDRs) of the studied beta-blockers were in the range of 5-200 mu mol L-1 and the lowest limit of detection (LOD) value was determined for pindolol (LOD = 1.96 mu M mu mol L-1). The highest LOD value was 4.96 mu mol L-1 found for nebivolol. In addition, physicochemical parameters such as the formal Galvani potential difference (Delta aqorg phi), formal Gibbs free energies of the ion transfer reaction (Delta aqorgG ') and partition coefficients (log P ' aq/org) for all studied molecules were determined. The latter were compared and correlated with the available literature values of log Poctanol. Finally, a standard addition method was used to determine the concentration of nebivolol in pharmaceutical preparations using a platform based on the electrified liquid-liquid interface. An electrochemical study of beta-blockers at the electrified liquid-liquid interface and their detection in pharmaceutical formulations.