Spectrophotometric determination of frusemide by its oxidation with ceric ammonium sulphate

Abstract

A simple and sensitive spectrophotometric method is described for the determination of frusemide (FRU). The method is based on the reaction of FRU with measured excess of ceric ammonium sulphate (CAS) followed by the determination of unreacted oxidant using xylene cyanol FF (XC) (Method A) and safranin O (SAF) (Method B). The reaction mixture exhibited maximum absorbance at 612 nm (Method A) and 526 nm (Method B). The calibration graph was linear from 20.00 to 30.00 µg mL^-1and 6.00 to 16.00 µg mL^-1for methods A and B respectively. The apparent molar absorptivity and Sandell’s sensitivity for method A and B were calculated to be 1.160×10⁴ L mol^-1cm^-1, 2.025<img src='/image/spc_char/cross.gif' border=0>10⁴L mol^-1 cm^-1 and 2.82×10^-3µg cm^-2, 0.0163 µg cm^-2 respectively. The method has been applied for the determination of frusemide in pure and dosage forms.