Determination of captopril on a coated capillary by capillary electrophoresis

Capillary electrophoresis with a coated capillary was applied to the determination of captopril, an inhibitor of the angiotensin-converting enzyme. The proposed method using a 100 mM sodium phosphate buffer pH 5.5 and salicylic acid as an internal standard was developed for the quantitative determination of captopril in commercially available pharmaceuticals.