PVC Membrane Electrode Modified by Lawson as Synthetic Derivative Ionophore for Determination of Cadmium in Alloy and Wastewater

In this study, a PVC membrane electrode was modified by a derivative of lawason that is a neutral ionophore for Cd (II) determination in alloy and wastewater as real samples. The modified electrode showed a linear electrochemical response to Cd (II) concentration between 5.0×10^−8 to 1.5×10^−1 molL-1 (LOD = 2.51×10^−8 molL-1). In selecting and determining the level of an effective composite of the membrane, the highest results were achieved in the membrane composition 33% PVC, 64.0% TEHP, 1.5% NaTPB, and 1.5% ionophore. The time it takes for the response to reach its maximum and remain stable at this electrode is very favorable (response time 12 s). The responses of the electrode in consecutive uses for two months did not deviate significantly. In investigating the disturbance of other ions and compounds in the measurement of cadmium, the designed electrode had a very good selectivity for cadmium. The best conditions for measuring cadmium with this electrode are in an acidic environment (pH range of 2.8–6.5). In this research, potentiometric titration with the use of chromate as titrant was used in water and alloy samples.