Selective determination of Cr(III) ions with novel potentiometric electrodes

Abstract Background Ionophores in the composition of potentiometric ion‐selective electrodes interact directly with the analyte ion and enable the determination of ionic species in various samples. Objectives In this study, a novel ion‐selective electrode based on 5‐bromosalicylaldehyde thiosemicarbazone was developed for the selective determination of Cr 3+ ions. Methods The optimum electrode composition contained ionophore, poly (vinyl chloride) (PVC), bis (2‐ethylhexyl) sebacate (BEHS) and potassium tetrakis ( p ‐chlorophenyl) borate (KT p ClPB) in ratios of 4.0: 61.0: 34.0: 1.0 (mg), respectively. Potential measurements were performed using a computer‐controlled multi‐channel potentiometric measurement system. Results The developed Cr (III)‐selective electrode exhibited a low detection limit of 3.96 × 10 −6 M over a wide concentration range of 1.0 × 10 −5 – 1.0 × 10 −1 M ( R 2 : 0.9979). The electrode exhibited good selectivity towards Cr 3+ ions among metal ions with different charges. The chromium (III)‐selective electrode, which exhibited highly reproducible results in three different concentration ranges, also had a very fast response time of 5 s. Conclusions The developed Cr (III)‐selective electrode were successfully performed in various beverage samples. As a result, the proposed electrode can be an alternative to other analytical methods in the analysis of Cr 3+ ions.