Spectrophotometric Determination of Furosemide Based on Its Complexation with Fe(III) in Ethanolic Medium Using a Flow Injection Procedure

摘要

A fast flow injection procedure with spectrophotometric detection based on the furosemide complexation with Fe(III) ions in ethanolic media is described.As carrier the flow single line system configuration used an ethanolic 10~(-2) mol L_1 Fe(III) solution flowing at 1.0 mL min-1,a 50 cm sample loop (250 mu L total sample injection),and a 50 cm long reactor coil,at room temperature.The detection at 513 nm presented a linear dynamic range from 1.00 x 10~(-4) to 1.00 x 10~(-2) mol L-1,obeying the linear equation Abs = 8.9 x 10~(-3) + 22.3 x [furosemide] (r = 0.998,n = 7).The limit of detection (3sigma/slope) was 3.00 x 10~(-5) mol L-1.The proposed method was applied to four commercial samples from different suppliers,as tablets and ampoules,and a synthetic urine sample spiked with the analyte without an effect from the other substances present in the formulation.The proposed procedure presented an analytical frequency of 95 measurements per hour.The results agreed with those from both the label and those determined by a spectrophotometric comparative procedure.Recoveries close to 100% were found in the commercial formulations and synthetic urine matrixes.