caa a22 4500 469038527 CHVBK 20180323132802.0 cr unu---uuuuu 170328e19921001xx s 000 0 eng 10.1007/BF00811540 doi (NATIONALLICENCE)springer-10.1007/BF00811540 Voltammetric studies on composition and stabilities of complexes of tetracycline and oxytetracycline with some metal ions in aqueous medium [Elektronische Daten] [M. Ghandour, H. Azab, Ahmed Hassan, A. Ali] Voltammetrische Untersuchungen zur Zusammensetzung und Stabilität von Komplexen von Tetracyclin und Oxytetracyclin mit einigen Metallionen in wäßrigem Medium Summary: The composition and stability of complexes of tetracycline and oxytetracycline with Cu(II), Cd(II), Pb(II) and UO2(II) have been studied polarographically (direct current and differential pulse polarographic techniques) at 25±0.1°C. Differential pulse polarographic studies have been particularly helpful in deciding the nature of metal-drug interactions at low concentrations. The reduction of Cu(II)-tetracycline has been found to be irreversible and diffusion controlled with the presence of an adsorption component. In the system uranyl(II)-tetracycline the complex formed has a stoichiometry of 1:1 and logK ox=4.04 which is very close to that obtained by potentiometric measurements. The peak half widthW 1/2 of the Pb(II)-OTC system is 60 - 70mV indicating that the process is reversible and two electrons are consumed. The log β′ is 10.30 in 0.1 mol dm−3 NaClO4. In the Cu(II)-OTC system two complexes were formed with log β1′=8.50 and log β2′=14.10. Cyclic voltammograms were recorded using a hanging dropping mercury electrode for the systems Cu(II), Cd(II), Pb(II) and UO2(II)-OTC to examine the irregularities in both peak potentials and peak currents during the polarographic investigations. Springer-Verlag, 1992 Voltammetric studies nationallicence Complexes nationallicence Tetracycline nationallicence Oxytetracycline nationallicence Ghandour M. Department of Chemistry, Faculty of Science, Assiut University, Assiut, Egypt aut Azab H. Department of Chemistry, Faculty of Science, Assiut University, Assiut, Egypt aut Hassan Ahmed Department of Chemistry, Faculty of Science, Assiut University, Assiut, Egypt aut Ali A. Department of Chemistry, Faculty of Science, Assiut University, Assiut, Egypt aut Monatshefte für Chemie / Chemical Monthly Springer-Verlag 123/10(1992-10-01), 853-864 0026-9247 123:10<853 1992 123 706 https://doi.org/10.1007/BF00811540 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00811540 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ghandour M. Department of Chemistry, Faculty of Science, Assiut University, Assiut, Egypt aut NATIONALLICENCE 700 1- Azab H. Department of Chemistry, Faculty of Science, Assiut University, Assiut, Egypt aut NATIONALLICENCE 700 1- Hassan Ahmed Department of Chemistry, Faculty of Science, Assiut University, Assiut, Egypt aut NATIONALLICENCE 700 1- Ali A. Department of Chemistry, Faculty of Science, Assiut University, Assiut, Egypt aut NATIONALLICENCE 773 0- Monatshefte für Chemie / Chemical Monthly Springer-Verlag 123/10(1992-10-01), 853-864 0026-9247 123:10<853 1992 123 706 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer