[Preparation and evaluation of new ion-exchange chromatographic stationary phase for the use in high performance...

A new method for the bonding of diethylamine(DEA) on the surface of silica to prepare novel hydrophilic packings for HPLC has been studied. After allyl glycidyl ether being synthesized, the Si-DEA anion-exchange bonded phase was prepared by the reaction of the double bond in allyl group with Si-H silica. The bonded phases obtained were characterized by elemental analysis, diffuse reflectance infrared Fourier transform(DRIFT) spectroscopy and HPLC evaluation. The methods were used for both porous silica and monodisperse non-porous silica. The contents of carbon, hydrogen and nitrogen of porous Si-DEA packing (MPS-DEA) were 3.31%, 0.95% and 1.34% respectively and those of monodisperse non-porous Si-DEA packing (NPS-DEA) were 2.55%, 0.97% and 0.96% respectively. The diethylamine absorption peak can be observed at 2970 cm-1 from the Si-DEA silica DRIFT spectrum. These data revealed that the diethylamine had been bonded on MPS-DEA and NPS-DEA packings. In HPLC tests, nucleotides and nucleosides such as cytosine, uracil, cytidine-5'-monophosphate, adenosine-5'-monophosphate, inosine-5'-monophosphate and guanosine-5'-monophosphate were satisfactorily separated on the porous anion-exchange packing (MPS-DEA), and a group of proteins (lysozyme, ribonuclease, ovalbumin, bovine serum albumin, insulin and gamma-globulin) were separated within 15 minutes successfuly. All test results indicated that the new method for preparing better anion-exchange silica packings is effective for both porous silica and monodiperse non-porous silica.