A sequential injection analysis system based on the formation of the cation FeSO4+ and the spectrophotometric measuring of the absorbance at 355 nm has 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 deviation (RSD) obtained was smaller than 2.4%. The linearity of response was obtained between 10 and 1000 mg L-1. The sampling rate was 72 samples per hour.
flow system; spectrophotometric analysis; sequential injection analysis; sulphate
