Sequential injection analysis determination of sulphate in wastewaters by ultraviolet-spectrophotometry

A sequential injection analysis system based on the formation of the cation FeSO4+ and the spectrophotometric measuring of the absorbance at 355 nm ha s been developed for the determination of sulphate in wastewaters. The main interferents were also evaluated. The proposed system is fully automatized and is able to monitor sulphate in samples. The relative standard deviatio n (RSD) obtained was smaller than 2.4%. The linearity of response was obtai ned between 10 and 1000 mg L-1, The sampling rate was 72 samples per hour.