Abstract

A simple and rapid spectrophotometric method for the determination of sulphide has been developed using flow injection analysis. The proposed method is based on the reducibility of sulphide ion towards Alizarin red S resulting in an intense red complex with a suitable absorption peak at 515nm. The absorbance value of this compound is directly proportional to the concentration. Optimum conditions for determining sulphide were investigated by a univariate method. Under the optimum conditions, a linear calibration graph was obtained over the range 0.01-4.0mg l-1, the detection limit was 4.0μg l-1, the relative standard deviation was 1.04% (n=13) and the standard addition recovery was between 103.7% and 106.0%. The method has been satisfactorily applied for the determination of sulphide in tannery effluents.