The invention relates to an alkane sulfonic acid or sulfonate composition, which comprises a monosubstituted alkane substituted by one sulfonic acid or sulfonate group and optionally a disubstituted alkane substituted by two sulfonic acid or sulfonate groups, wherein if the composition comprises said disubstituted alkane the molar ratio of the monosubstituted alkane to the disubstituted alkane is equal to or higher than 12:1. Further, the invention relates to a process for treatment of an alkane sulfonic acid or sulfonate composition, wherein substantially all of the disubstituted alkane is removed or the disubstituted alkane is removed to such extent that the molar ratio of the monosubstituted alkane to the disubstituted alkane is increased to a value which is equal to or higher than 12:1. Still further, the invention relates to a method of treating a hydrocarbon containing formation using such composition, containing no or less disubstituted alkane, as surfactant.
