Poster Presentations
Day 2, June 11（Thu.） Room P (5F 501+502)
- 2P-13
Enhanced Ionization of Oligonucleotides by Hydrophilic Additives in LC/MS
(1UOsaka, 2UOsaka, 3Shimadzu)
oTakashi Miyazaki1,2,3, Satoshi Yamaki3, Takao Yamaguchi1, Satoshi Obika1
Oligonucleotide therapeutics, produced by multi-step solid-phase synthesis, often contain diverse low-level impurities that closely resemble the desired product. Comprehensive analytical characterization is therefore essential to ensure product safety and efficacy. Liquid chromatography/mass spectrometry (LC/MS) with reversed-phase ion-pair separation and electrospray ionization (ESI) is a standard tool for such analysis. 1,1,1,3,3,3-Hexafluoro-2-propanol (HFIP) is widely used for the mobile phases to enhance ESI efficiency. However, HFIP has several challenges, including environmental concerns as a per- and polyfluoroalkyl substance (PFAS), limited mobile phase stability, and high cost, motivating the development of HFIP-free analytical methods for oligonucleotides. We previously reported that hydrophilic additives such as glycine can enhance oligonucleotide ionization under the acetic acid/triethylamine mobile phase conditions, which are inefficient for ESI. In this study, we aimed to clarify the role of hydrophilic additives in ESI and to establish an HFIP-independent LC/MS for oligonucleotides by systematically investigating how analytical method parameters affect the ionization enhancement afforded by glycine. Our findings indicate that glycine is particularly effective under analytical settings with reduced desolvation efficiency, suggesting that glycine acts primarily during the early ESI process, immediately after droplet formation and during the initial stages of desolvation.