FLOW-INJECTION EXTRACTION SPECTROPHOTOMETRIC DETERMINATION OF SALBUTAMOL BY OXIDATIVE COUPLING WITH 4-AMINO-N,N-DIMETHYLANILINE

Salbutamol can be determined spectrophotometrically at 605 nm after flow-injection extraction into chloroform after oxidative coupling with 4-amino-N,N-dimethylaniline. The carrier stream is distilled water and the reagents streams contain 5% (w/v) sodium hydrogencarbonate, 0.5% (w/v) potassium hexacyanoferrate(III) and 0.1% (w/v) 4-amino-N,N-dimethylanilinium sulphate. The sampling rate is 20 h-1. The calibration graph is linear up to 20.0-mu-g ml-1 salbutamol, based on injection volume 100-mu-l. The relative standard deviation (n = 10) was 1.9% for 10-mu-g ml-1 salbutamol. The system has been applied to the determination of salbutamol in pharmaceutical formulations.