Highly selective chromium(III) PVC-membrane electrodes based on some recently synthesized Schiff's bases

Three recently synthesized Schiff's bases were studied to characterize their ability as Cr3+ ion carrier in PVC-membrane electrodes. The polymeric membrane (PME) and coated glassy carbon (CGCE) electrodes based on 2-jydroxybenzaldehyde-O,O'-(1,2-dioxetane-1,2-diyl) oxime (L1) exhibited Nernstian responses for Cr3+ ion over wide concentration ranges (1.5 x 10(-6) M for PME and 2.0 x 10(-7) M for CGCE). The proposed potentiometric sensors manifest advantages of relatively fast response and, most importantly, good selectivities relative to a wide variety of other cations. The selectivity behaviour of the proposed Cr3+ ion-selective electrodes revealed a considerable improvement compared to the best previously PVC-membrane electrodes for chromium(III) ion. The potentiometric responses of the electrodes are independent of pH of the test solution in the pH range 3.0-6.0. The electrodes were successfully applied to determine chromium(III) in water samples.