DERIVATIZATION GAS-CHROMATOGRAPHIC DETERMINATION OF CAPTOPRIL

An improved method with derivatization and gas chromatography (GC) is described for the determination of captopril, an antihypertensive agen t. The method is based on the derivatization of captopril with pentafl uorobenzyl bromide in acetonitrile, using potassium carbonate as a bas e catalyst. Under a mild condition, the highly polar and nonvolatile c aptopril was derivatized into a derivative with suitable chromatograph ic properties. The resulting derivative was separated on an OV-1 colum n and monitored with a flame-ionization detector (FID). The linear ran ge of the method for the determination of captopril was over 0.25-4.00 mu mol. The detection limit (signal-to-noise ratio = 3) of captopril was about 40 nmol. The method was satisfactorily applied to the analys is of captopril in tablets.