ELECTROCHEMICAL INVESTIGATION OF Cd(II) WITH ANTIBIOTICS AS PRIMARY LIGANDS AND CEFOTAXIME AS SECONDARY LIGAND. A POLAROGRAPHIC STUDY

摘要

The polarographic study of Cd~(2+) using doxycycline, chlortetracycline, oxytetracycline, tetracycline, minocycline, amoxicillin and chloramphenicol as primary ligands and cefotaxime as secondary ligand has been reported at pH = 7.30 ± 0.01, μ = 1.0 M KNO3 at 25°'C. Cd~(2+) formed 1:1:1, 1:1:2 and 1:2:1 complexes. The stability constant (Ig P) varied from 1.98 to 9.73 showed that these drugs or in combination with cefotaxime or their metal complexes could be used for investigation of Cd~(2+) toxicity. The trend in stability, viz. enthalpy change (ΔH), free energy change (ΔG) and entropy change (Δ5) were also determined. The electrode processes were reversible and diffusion-controlled. A small variation in potential not only affects the rate but rate constant greatly.