Preparation and characterization of a sulindac sensor based on PVC/TOA–SUL membrane

•The new sulindac ion-selective electrode based on ion-pair complex was prepared.•The electrode exhibits favorable analytical parameters. The limit of detection is 1.4 × 10− 5 mol L− 1.•The notably properties are high selectivity, low cost, and a very long lifetime — 3 months.•The electrode was applied for determination of sulindac in urine samples.

A potentiometric sulindac sensitive sensor based on tetraoctylammonium (Z)-5-fluoro-2-methyl-1-[[p-(methylsulfinyl)phenyl]methylene]-1H-indene-3-acetate (TOA–SUL) was described. The electrode responded with sensitivity of 57.5 ± 1.6 mV decade− 1 over the linear range 5 × 10− 5–1 × 10− 2 mol L− 1 at pH 6.0–9.0. It had the limit of detection 1.4 × 10− 5 mol L− 1, a fast response time of 13 s and showed clear discrimination of sulindac ions from several inorganic and organic compounds and also amino acids. This electrode did not contain any inner solutions, so it was easy and comfortable to use. The proposed sensor was used to determine sulindac in clear solution and in urine sample solution.