The potentiometric response of salicylate electrode based on complex of (1,8-diamino-3,6-dioxaoctane) nickel(II) was studied. The complex of 1,8-diamino-3,6-dioxaoctane nickel(II) [Ni(DADOO)] was used as carrier into plasticized polyvinyl chloride (PVC) membrane. The influence of several variables was investigated in order to optimize the potentiometric response and selectivity of the electrode. The resulting membrane electrode incorporating 29% PVC, 63% dioctylphthalate (DOP) as plasticizer, 2% methyltrioctylammonium chloride (MTOAC) as cationic additive and 6% carrier (all m/m) demonstrated a Nernstian response of -59.5 ± 1.0 mV decade-1 over the concentration range of 7.0 × 10-7- 1.0 × 10-1 mol L-1 salicylate. The electrode exhibited a fast response time (< 20 s) with detection limit of 5.0 ×10-7 mol L-1, and can be used over a wide pH range of 6.0-9.5. It was successfully applied to the determination of salicylate ion in real samples.
salicylate ion-selective electrode; PVC membrane; potentiometry; salicylate analysis; Ni-complex
