Assay of dipyridamole in human serum using cathodic adsorptive square-wave stripping voltammetry

A rapid and sensitive square-wave voltammetric procedure was optimized for the determination of dipyridamole after its adsorption preconcentration onto a hanging mercury drop electrode. The peak cur-rent of the first of the two peaks developed for this drug in Britton-Robinson buffer at pH 8.0 has been considered for the present analytical study. An accumulation potential of -1.0 V versus Ag/AgCl/KCls, pulse amplitude a =100 mV, scan increment DeltaE = 10 mV, and frequency f = 120 Hz were the optimal experimental parameters. Dipyridamole can be determined in the concentration range of 9.0x10(-9) to 5.0x10(-6) M using accumulation times of 30-300 s. A detection limit of 4.0x10(-11) M was achieved after a 300 s accumulation time. Applicability to serum samples was illustrated. The average recoveries for dipyridamole spiked to serum at 0.25-4.50 mug ml(-1) were 96.0-102.0%, and the higher standard deviation was 2.9%. A detection limit of 0.06 mug mL(-1) of serum was obtained.