Determination of procaine hydrochloride by ion-pairing flow injection analysis with piezoelectric detection

A fast and simple method for the determination of procaine hydrochloride by ion-pairing flow injection analysis has been developed. It is based on the formation of an ion-pair with sodium dodecyl phenylsulphonate and piezoelectric detection. The calibration curve was linear between 0.02 and 2.00 mg/mL, with a detection limit of 0.01 mg/mL, a relative standard deviation of 0.3% (10 replicates) and a sampling frequency of 120/h. The proposed method has been satisfactorily applied to the determination of procaine hydrochloride in pharmaceutical preparations.