Abstract

Poster Presentations

Day 3, June 12（Wed.）　　Room P1 (Multipurpose Hall)・Room P2 (Conference Room 101+102)

For the quality control of synthetic oligonucleotides, ion-pair reversed phase chromatography (IP-RPC) using alkylamine and hexafluoroisopropanol (HFIP) as additives in the eluents is usually used for LC/MS analysis. However, under this RPC conditions, in addition to the problem of contamination of the ion source with ion-pairing reagents, the separation selectivity of homologues or isomers is lower than that of ion exchange chromatography (IEC). We have previously investigated the separation of oligonucleotides using hydrophilic interaction chromatography (HILIC) column packed with hydrophilic stationary phase of silica-gel with carbamoyl group and have found that separation selectivity different from that of IP-RPC can be obtained. In this study, we attempted to improve separation by evaluating the effects of functional group types, column materials and various separation conditions on retention behavior. As a result of examining the optimum analytical conditions, the separation selectivity of homologues or isomers formed by phosphorothioation was better than that of IP-RPC and almost equivalent to that of IEC. Furthermore, as a result of investigating the possibility of increasing sensitivity by using a make-up liquid, it was found that sensitivity could be improved by using a methanol solution containing ammonium.

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