Abstract: Aqueous solutions of alkali metal C.sub.8-22 .alpha.-olefin sulfonates of light color and of low sultone content are prepared rapidly and at moderate temperatures by:(a) reacting a C.sub.8-22 .alpha.-olefin with gaseous sulfur trioxide thereby forming a crude sulfonation product mixture containing C.sub.8-22 olefin sulfonic acids, with a content of sultones,(b) bleaching said crude sulfonation product mixture at 30.degree. C. to 80.degree. C. for 10 to 60 minutes with an aqueous alkaline bleaching solution at a pH of at least 8,(c) heating said diluted bleached sulfonation product mixture containing excess alkali to a temperature of from 140.degree. C. to 170.degree. C. until the sultone content of said sulfonation product mixture is less than 100 ppm, and(d) recovering said alkali metal C.sub.8-22 .alpha.-olefin sulfonates of light color and of low sultone content. A decrease in the sultone content from as much as 650,000 ppm to less than 50 ppm is possible by the method.