A Poly(Vinyl Chloride) Membrane Electrode for the Determination of the Diuretic Furosemide

ABSTRACT New polymeric electrode responding to furosemide was constructed by incorporating the furosemide–aliquat ion pair complex into a poly(vinyl chloride) (PVC) membrane. The electrode exhibited a linear response over the concentration range 1.59 × 10−4–1.00 × 10−2 mol L−1, a detection limit of 1.19 × 10−4 mol L−1 with E = −245.6 − 58.9log[Fur]. The pH did not affect the response of the electrode within the range 7.0–10.0. Direct potentiometry was used to assay furosemide in pharmaceutical preparations. The results were compared with those obtained with spectrophotometric and chromatographic reference methods.