Sensing and quantification of gatifloxacin in real wastewater effluents using solid-contact ion-selective membranes

Purpose: To determine gatifloxacin hydrochloride (GTF) levels in real wastewater effluents. Methods: In the last few years, the application of membrane-sensitive electrodes in the analysis of active pharmaceutical ingredients (APIs) has become a topic of paramount importance. Two ionselective electrodes (ISEs) were fabricated using phosphotungstic acid (PTA) and sodium tetraphenylborate (TPB) as ion combining principles, for selective cum sensitive determination of gatifloxacin hydrochloride (GTF) in factory wastewater effluents. The membranes were successfully fabricated, and their performance was optimized. A validation scheme that followed IUPAC guidelines was implemented in the application of the sensors for sensitive determination of gatifloxacin hydrochloride. Results: The fabricated membranes quantified the studied drug in a concentration range of 1 - 10⁴ µM, with GTF-PTA and GTF-TPB electrodes showing gradients of 56.6 ± 0.40 and 57.8 ± 0.50 mV/decade, respectively. The fabricated sensors showed excellent working criteria in a pH range of one to five. A validation scheme was applied to the proposed method with respect to accuracy, robustness, and ruggedness. The suggested analytical procedure was effectively used for sensitive quantification of GTF in bulk form and in actual industrial water effluents. Conclusion: The proposed method has been efficiently applied for the determination of GTF in wastewater samples without any sample pretreatment.