A new type of a reactor column, a crushed BaSO 4 reactor column used for the flow injection spectrophotometric determination of sulfate ion using the exchange reaction of sulfate ion and barium-dimethylsulfonazo III is proposed. The column is very simple and economical. It can be continuously used for 8h before washing with water for repeated usage of at least 1 month. The procedure is sensitive. Application to various water samples was demonstrated.