SEPARATION PROPERTIES OF A MIXED-MODE STATIONARY PHASE: HYDROPHILIC INTERACTION LIQUID CHROMATOGRAPHY SEPARATION OF B-VITAMINS

摘要

In this work, the chromatographic behaviours of B vitamins consisting of Bl,B2,B3,B5,B6 and B12 were investigated to understand their hydro-philic interaction and mixed-mode separation mech-anisms on a recently developed mixed-mode station-ary phase,le-PBA-Mix. A mixed-mode separation mechanism makes possible a precise description of chromatographic retention and separation process of analytes on a multifunctional stationary phase. This mechanism depends mostly on the structural proper-ties of solutes adsorbing on the surface of the station-ary phase, and content of the mobile phase. The pres-ence of buffer salt ions also effects the interaction between solutes and the stationary phase. Several chromatographic conditions including pH, tempera-ture and buffer concentration for separation six B vit-amins on lle-PBA-Mix column have been tested. The results show that pH and buffer concentration has significant effects on the separation of B vita-mins on Ile-PBA-Mix column. Eventually, the mo-bile phase containing a gradient elution linearly in-creasing from 15 to 60% of ammonium acetate buffer (50 mM,pH4.5)in acetonitrile was found to be most condition for separation of the six B vita-mins under HILIC conditions.