Nashwa M. H. Rizka*, Fathy A. EL-Sayedb, and Foud A. El-Sawadib
aEnvironmental Biotechnology Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), Minufiya University, Sadat City, Egypt. bChemistry Department, Faculty of Sciences, El-Qaseem University, Saudi Arab. ٭ Corresponding author; Tel.; +20482601267; Fax; +20482601266 E-mail address: nashwa05@yahoo.com
Summary: Levofloxacin (Le) or Lomefloxacin (Lo) is sensitively detected in pharmaceuticals by potentiometric method, based on the formation of an ion-pair complexes between levofloxacin or lomefloxacin cation and ammonium reinckate and flavinic acid. Two poly (vinyl chloride) conventional membrane sensors for each drug were fabricated, characterized, compared, and applied. The sensors exhibit linear response in the range of 1x10-2–1x10-4 M with cationic slopes of 53.2, 51.4 and 50.3, 48.5 mV decade-1 at 25°C over the pH range 4-6, for lomefloxacin and levofloxacin sensors, respectively. Both drug electrodes show reasonable selectivity towards some related compounds and inorganic cations. The prepared electrodes are successfully applied to the determination of levofloxacin or lomefloxacin in bulk powder and pharmaceutical products. Results with mean accuracy 99.7 %, 99.5 % and 99.1, 99.0 for the nominal concentrations were obtained for levofloxacin and lomefloxacin, respectively, which compare well with data obtained using spectrophotometric (UV-Vis) method. |
