Comparative Study of Different Ionophores in Ion Selective Electrodes for Stability indicating Determination of Moxifloxacin

Three novel moxifloxacin (MO) selective electrodes were investigated with 2-nitrophenyl octyl ether as a plasticizer in a polymeric matrix of polyvinyl chloride (PVC). Sensor 1 was fabricated using tetrakis(4-chlorophenyl)borate (TpClPB) as an anionic exchanger without incorporation of an ionophore. Sensor 2 used 2- hydroxyl β-cyclodextrin as an ionophore while sensor 3 was constructed using 4-tertary butyl sulfocalix-8-arene as an ionophore. Linear responses of MO within the concentration ranges of 10−5 to 10−2 mol L−1 were obtained using sensors 1, 2 and 3, respectively. Near Nernstian slopes of 49.79, 51.50and 52.10 mV/decade over the pH range of 2–5 were observed. The selectivity coefficients of the developed sensors indicated excellent selectivity for MO. The proposed sensors displayed useful analytical characteristics for the determination of MO in bulk powder, pharmaceutical formulation, and biological fluids (plasma) and in the presence of its alkaline degradation product and thus could be used for stability-indicating studies.