Potentiometric sensor for furosemide determination in pharmaceuticals, urine, blood serum and bovine milk

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.