Sensitive determination of captopril by time-resolved chemiluminescence using the stopped-flow analysis based on potassium permanganate oxidation

Four quantitative parameters adjustable via software settings, two of them typically kinetic parameters, such as rate of the light-development reaction and rate of the light-decay reaction, and the other conventional parameters, such as maximum emission intensity and total emission area, were used to obtain linear calibration graphs with each measurement parameter. The detection limits ranged from 0.011 to 0.026 μg mL−1 and R.S.D. values (n = 10) of 1.21-3.93 at a 0.50 μg mL−1 and 2.01-3.41 at a 1.60 μg mL−1 concentration levels were obtained. The method was satisfactorily applied to the determination of captopril in pharmaceutical preparations.