Comparison of retention of native cyclodextrins and its permethylated derivatives on porous graphite carbon and silica C18 stationary phases Original Research Article

The retention of the solute in the stationary phase is the effect of interaction between the solute and the stationary phase and the solute and the mobile phase (solvatation phenomena). Additionally, the components of the mobile phase can modify the surface of the stationary phase, and thus the change the interaction between the solute and the stationary phase. The current paper presents a systematic comparison of retention of α-, β- and γ-cyclodextrins (CD) and its permethylated derivatives on the porous graphitic carbon and RP C18 columns. From temperature study, the contribution of ΔH and ΔS to ΔG has been discussed. The physico-chemical interactions of cyclodextrins seem to be similar only in the case of native cyclodextrins (except γ-CD) with the RP C18 column when enthalpy–entropy compensation can be observed. In the case of permethylated cyclodextrins and the RP C18 column, interactions are only similar for individual alcohols. For the PGC column, the influence of individual interactions on individual cyclodextrins seems to be different.