Stability-indicating determination of ciprofloxacin in the presence of its main photo-degradation product using solid-contact electrodes in river water

The application of membrane sensors for monitoring and evaluation of pharmaceutical environmental contaminants has become a significant aim in the past few years. Due to the wide applicability of ciprofloxacin hydrochloride (CPF) in medicine, there is a high probability of its presence in the environment, especially in surface water like river water. The long-term exposure of the river water to sunlight and the photoliability of CPF may increase its photodegradation. Two selective and sensitive membrane electrodes were created to measure CPF when it is present with its main photo-degradant product. These were made using two ion pairing agents, which are sodium tetraphenylborate (TPB) and phosphotungstic acid (PTA). The linearity range of the manufactured electrodes was 1 × 10^-6–1 × 10^-2 M. The slopes of the CPF-TPB and CPF-PTA membrane electrodes are 60.1 ± 0.70 and 57.9 ± 0.90 mV/decade, respectively. The cited sensors showed adequate performance in a pH range from 2.0 to 5.0. All test parameters were fine-tuned to provide the best electrochemical performance. The manufactured membranes were successfully used to determine CPF in a sensitive way in the presence of its primary photodegradant. The cited sensors were effectively used to quantify CPF in river water samples, with no pre-treatment operations required.