Separation of strength and selectivity of mobile phase by spectral mappingtechnique

The retention behaviour of seven monotetrazolium and nine ditetrazolium sal ts was studied in seven different mobile phases on alumina and impregnated alumina stationary phases. The strength and selectivity of the components o f mobile phases were separately calculated by the spectral mapping techniqu e. It was established that tetrahydrofuran (THF) has the highest solvent st rength while the differences among ethanol, I-propanol, 2-propanol and diox ane were relatively low. The selectivity of THF was also considerably diffe rent from those of other solvents. Hydrophobicity and electronic parameters were equally involved in the retention strength and selectivity of tetrazo lium salts, indicating the mixed character of their interaction with the al umina stationary phase. Copyright (C) 2001 John Wiley & Sons, Ltd.