Development of potentiometric sunset yellow selective electrode and its applications

In this thesis, a potentiometric ion selective electrode (ISE) was used to determine the food colorant sunset yellow. Sunset yellow-Methyltrioctylammonium chloride ion pairs were synthesized. The synthesized ion pair was used as ionophore material in the structure of the electrode membrane. For membrane optimization, PVC membrane ion selective electrodes in different compositions were produced using synthesized ion pairs and potentiometric performance characteristics of these electrodes were investigated. It was determtined the best potentiometric performance characteristics exhibited the electrode which has the composition having 3.0 % sunset yellow-Methyltrioctylammonium (Sunset-MTOA) ion pair, 64.8 % nitrophenyloctyl ether (NPOE), 32.0 % polyvinylchloride (PVC) and 0.2 % potassium tetrakis (4-chlorophenylborate) (KTpClPB). It was revealed that. the linear operating range of this electrode was 1.0 × 10-5-5.0 × 10-2 M, the slope of the 10-fold concentration change was 23.6 mV, limit of detection was 1.0 × 10-5 M, pH operating range was 6.4-9.1, and the response time was ≈ 5 s. The electrode exhibited a highly reproducible potentiometric response.