a salt of sulphonic acid

Hydrocarbon in which a hydrogen atom has been replaced with the highly polar (SO2OX) group, where X is a metallic ion or alkyl radical. Petroleum sulfonates are refinery by-products of the sulfuric acid treatment of white oils. Sulfonates have important applications as emulsifiers and chemical intermediates in petrochemical manufacture. Synthetic sulfonates can be manufactured from special feedstocks rather than from white oil base stocks.

A sulfonate ion is an ion that contains the -S(=O)2-O− functional group. The general formula is RSO2O−, where R is some organic group. They are conjugate bases of sulfonic acids with formula RSO2OH.