Specific counterion effects on the formation and electrolytic dissociation of micelles have been studied for sodium dodecyl sulfate and hexadecyl-N,N,N-trimethyl ammonium bromide in the presence of different electrolytes. Mass spectrometry has been used to investigate the affinity of counterions to surfactant free monomers in the gas phase. Linear correlations have been found between the parameters determined for micelles in the aqueous phase and the fraction of counterions preferably bound to surfactant free monomers in the gas phase. The work presents a new insight into specific ion effects. (C) 2010 Elsevier Inc. All rights reserved.