A Novel Single-channel Continuous Flow Injection Spectrophotometry Determination of Nalidixic Acid through Oxidative Coupling Reaction

In this study, a novel sensitive and selective method was developed for the determination of nalidixic acid (NAL). The method utilizes ۴-aminoantipyrine (۴-AAP) as a coupling agent in an oxidative coupling reaction with NAL. The reaction between NAL and ۴-AAP, in the presence of potassium periodate (KIO₄) as oxidizing agent, produced a pink-violet colored product with a maximum absorption wavelength at ۵۳۰ nm. The linear calibration curve for the determination of NAL by developed continuous flow injection analysis/ merging zones technique (CFIA/MZT) method ranged from ۵ to ۴۰۰ µg mL⁻¹. The limit of detection (LOD) and limit of quantification (LOQ) of the method were obtained as ۱.۹۰ µg mL⁻¹ and ۶.۳۴ µg mL⁻¹, respectively. The method demonstrated excellent precision, with a relative standard deviation (RSD%) of ۰.۴۹%. The sampling rate achieved was ۸۰ samples per hour. The developed CFIA/MZT method was validated and compared with the official titration method outlined in the United States Pharmacopoeia (USP), showing favorable agreement.

کلیدواژه ها:

continuous flow injection analysis ، Nalidixic acid ، ۴-Aminoantipyrine ، pharmaceutics