FLOW-INJECTION SPECTROPHOTOMETRIC DETERMINATION OF CAPTOPRIL USING ONLINE SOLID-PHASE EXTRACTION

In the proposed procedure, the determination of captopril with Folin-C iocalteau reagent using a flow-injection analysis technique (FIA) with spectrophotometric detection at 740 nm is described. The negative eff ect of interfering substances is overcome by a solid phase extraction (SPE), when captopril is adsorbed on the solid phase in the microcolum n, which is integrated directly into the flow system. Pretreatment of the sample takes place directly in the flowing stream. With the SPE co lumn (quarternary ammonium), captopril was determined in the range fro m 2 to 50 mu g/ml (RSD = 0.85%) with a frequency of 30 to 60 samples p er hour.