Novel mefenamic acid PVC membrane sensor based on a new Cd Schiff's base complex containing a phenanthroline unit

Abstract

In this study, a PVC membrane electrode modified with a Cd Schiff base complex was constructed as a novel, sensitive and selective structured carrier for checking trace amounts of mefenamic acid in real samples. A novel macrocyclic Schiff base complex ([CdL²Cl]ClO₄·2H₂O) was synthesized via the Cd(II) templated [1 + 1] cyclocondensation of 2,9-dicarboxaldehyde-4,7-diphenyl-1,10-phenanthroline with N-(2-aminoethyl)-1,3-propanediamine. The effects of the parameters such as working solution pH, repeatability, reproducibility, response time and selectivity to mefenamic acid were investigated. This sensor responds to mefenamic acid in the wide linear range from 1.0 × 10⁻⁹ to 4.0 × 10⁻² mol L⁻¹ with a limit of detection of 5.01 × 10⁻⁹ mol L⁻¹ at pH 3–8.5. The proposed sensor has a fast response time and can be applied for at least 5 months without any significant divergence in the currents.