Abstract

A flow-injection spectrophotometric method for the determination of aluminium(III) has been described. The method is based on the reaction Al(III) with morin to form a yellow complex with maximum absorption at 425nm in the presence of cationic surfactant CPC and glacial acetic acid. In the presence of cationic surfactant CPC, the sensitivity of the chromogenic reaction was greatly improved. Under the optimized conditions, calibration graphs for Al(III) are linear in the range 5-150g l-1 with a detection limit of 0.0125g l-1 (3σ). The reproducibility was satisfactory with a relative standard deviation of 1.7% for ten determinations of 50μg l-1 Al(III). With a sample solution of 450μl being injected, the sampling frequency is 60/h.