HOW TO FREELY CHANGE THE POLARITY OF THE STATIONARY-PHASE IN A LIQUID-CHROMATOGRAPHIC COLUMN

The concept of changing the polarity of the stationary phase in a liqu id chromatographic column is developed. Three phases are presented whi ch all contain a sulfur atom in the sulfide form. On oxidation of the sulfur atom with iodosobenzene in the packed column, a sulfoxide group is formed which is considerably more polar. This change can be perfor med in infinitesimally small steps and convert the phase from essentia lly unpolar to quite polar. The polarity change is reversible. The sep aration of several classes of compounds on these new phases in both th e oxidized and the reduced forms is compared with that on traditional phases.