Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, China. Electronic address: [Email]
Stationary phases with multiple-mode mechanism are beneficial to meet the needs of complex samples, but there are few multiple-mode stationary phases which can adjust the relative strength among multiple-forces imposed on the solutes. This work presents a facile preparation method of reverse-phase/hydrophilic interaction/ion-exchange tri-mode stationary phase, in which three functional monomers, lauryl methacrylate (LMA), hydroxyethyl methylacrylate (HEMA) and dimethylaminoethyl methacrylate (DMAEMA) as co-monomers underwent surface initiated-atom transfer radical polymerization (SI-ATRP) on the surface of silica. The structure of stationary phases was characterized and their chromatographic properties were investigated using various solutes. By comparison with classical single-mode columns, it is found that the newly designed columns can offer multiple interactions including hydrophobic, hydrophilic and electrostatic interactions and show good separation abilities to the tested solutes. Besides, changing the ratios of LMA, HEMA and DMAEMA in SI-ATRP system can easily adjust the relative strength of three interactions imposed on the solutes, inducing adjustable separation selectivity of the columns. The improved separation of multivitamin sample and the successful use of the columns in Per aqueous liquid chromatography indicate the potential of the tri-mode stationary phases.