Ytterbium(III)-selective membrane electrode based on cefixime Original Research Article

We have discovered that the antibiotic cefixime (CFI) can be used as a suitable ionophore in PVC membranes having interesting response characteristics for Yb3+ ions. The selective complexation behavior of cefixime with Yb3+ over different metal ions was studied in DMSO solution. The negligible water solubility of cefixime and the increased stability and selectivity of its Yb3+ complex make the antibiotic an attractive ionophore for use in potentiometric poly (vinyl chloride) membrane electrodes for Yb3+. The results revealed a Nernstian response to Yb3+ over concentration range 1.0×10−2–1.0×10−6 M as well as improved selectivity against a wide range of common interferences. The sensor possesses a detection limit of 7.0×10−7 M and can be used in a pH range 3.0–8.0 for at least 8 weeks.