Debalkie Ameha, Guadie Atnafu, Kassa Adane, Tefera Molla
Department of Chemistry, College of Science, University of Gondar, Gondar 196, Ethiopia.
Department of Chemistry, College of Natural and Computational Sciences, Debre Markos University, Debre Markos 269, Ethiopia.
ACS Omega. 2023 Jul 10;8(29):25758-25765. doi: 10.1021/acsomega.3c00805. eCollection 2023 Jul 25.
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 of the effective surface area of the modified electrode and decreased charge-transfer resistance confirmed surface modification of the GCE by a conductive poly(ANSA) film. The appearance of an oxidative peak without a reductive peak in the reverse scan direction showed the irreversibility of the electrochemical oxidation of NFN in both the bare GCE and poly(ANSA)/GCE. A better coefficient of determination for the peak current on the square root of the scan rate ( = 0.99514) than the scan rate ( = 0.97109), indicating the oxidation of NFN at the poly(ANSA)/GCE, was predominantly diffusion mass transport-controlled. Under optimized pH and square wave parameters, the voltammetric current response of NFN at the poly(ANSA)/GCE showed linear dependence on the concentration, ranging from 1.0 × 10 to 4.0 × 10 M with a limit of detection of 4.1 × 10. The NFN level in the studied tablet brands was in the range of 90.30-103.3% of their labeled values. Recovery results in tablet and urine samples ranged from 98.35 to 101.20% and 97.75 to 99.60%, respectively, and interference recovery results were less than 2.13% error in the presence of ampicillin, chloroquine phosphate, and cloxacillin. The present method had a better performance for the determination of NFN in tablet formulations and urine samples as compared with recently reported voltammetric methods due to its requirement of a simple electrode modification step, which provides the least limit of detection and a reasonably wider linear dynamic range.
在本研究中，采用聚（8-氨基萘-2-磺酸）对玻碳电极进行动电位修饰[聚（ANSA）/玻碳电极]，用于检测片剂制剂和人体尿液样本中的诺氟沙星（NFN）。修饰电极有效表面积的增加和电荷转移电阻的降低证实了导电聚（ANSA）膜对玻碳电极的表面修饰。在反向扫描方向上出现氧化峰而无还原峰，表明在裸玻碳电极和聚（ANSA）/玻碳电极中，NFN的电化学氧化均不可逆。扫描速率平方根的峰电流测定系数（=0.99514）优于扫描速率（=0.97109），表明聚（ANSA）/玻碳电极上NFN的氧化主要受扩散传质控制。在优化的pH值和方波参数下，聚（ANSA）/玻碳电极上NFN的伏安电流响应与浓度呈线性关系，范围为1.0×10至4.0×10 M，检测限为4.1×10。所研究片剂品牌中的NFN水平在其标示值的90.30 - 103.3%范围内。片剂和尿液样本的回收率分别为98.35%至101.20%和97.75%至99.60%，在氨苄西林、磷酸氯喹和氯唑西林存在下，干扰回收率误差小于2.13%。与最近报道的伏安法相比，本方法在片剂制剂和尿液样本中NFN的测定方面具有更好的性能，因为它只需简单的电极修饰步骤，检测限最低，线性动态范围较宽。
