“…Since geometry plays such an important role in ion-binding, the structural complexity of selective ionophores for anions tends to be greater, in general, than for cations. 14 The facts that acridinium derivatives are used as ionophores in construction of optical sensors 15 and pyridinium derivatives form stable complexes 16,17 with CrO 4 2and Cr 2 O 7 2-, suggests that an acridinium based membrane would effectively interact towards Cr(VI) anions. In this paper, a new, simple, sensitive and reproducible electrode with a PVC based membrane is described for the determination of Cr(VI) anions.…”