The construction, evaluation and analytical application of a potentiometric sensor, namely, Pt|Hg|Hg2(Fur)2|Graphite, where Fur stands for 4-chloro-N-furfuryl-5-sulphamoyl-anthranilate ion, are described. This electrode has a linear dynamic range between 5.0 × 10-7-1.0 × 10-2 mol L-1 with a near-Nernstian slope of (-58.4± 0.9) mV decade-1 and a detection limit of 3.8 × 10-7 mol L-1. The potentiometric response is independent of the pH of the solution in the pH range 7.0-9.0. The electrode shows easy construction, low-cost, fast response time (within 10-20 s) and can be used for a period of 6 months without significant change in its performance characteristics. The proposed sensor displayed good selectivities over a variety of other anions (carboxylates and inorganic anions). Application of this potentiometric sensor for the furosemide determination in pharmaceuticals, urine, blood serum and commercial milk samples is reported.
4-cloro-N-furfuryl-5-sulphamoylanthranilate-sensitive electrode; potentiometry; pharmaceuticals; urine; human blood serum; bovine milk
