Selective Determination of Norfloxacin in Pharmaceutical Formulations and Human Urine Samples Using Poly(8-aminonaphthaline-2-sulfonic Acid)-Modified Glassy Carbon Electrodes

In this study, a glassy carbon electrode was modified potentiodynamically with poly(8-aminonaphthaline-2-sulfonic acid) [poly(ANSA)/GCE] for the detection of norfloxacin (NFN) in tablet formulations and human urine samples. Improvement effective surface area decreased charge-transfer resistance confirmed modification GCE by conductive poly(ANSA) film. The appearance an oxidative peak without reductive reverse scan direction showed irreversibility electrochemical oxidation NFN both bare poly(ANSA)/GCE. A better coefficient determination current on square root rate (R2 = 0.99514) than 0.97109), indicating at poly(ANSA)/GCE, predominantly diffusion mass transport-controlled. Under optimized pH wave parameters, voltammetric response poly(ANSA)/GCE linear dependence concentration, ranging from 1.0 × 10–8 to 4.0 10–4 M limit 4.1 10–10. level studied brands range 90.30–103.3% their labeled values. Recovery results samples ranged 98.35 101.20% 97.75 99.60%, respectively, interference recovery were less 2.13% error presence ampicillin, chloroquine phosphate, cloxacillin. present method had performance as compared recently reported methods due its requirement simple step, which provides least reasonably wider dynamic range.