Novel Hydrophilic-Phase Extraction, HILIC and High-Resolution MS Quantification of an RNA Oligonucleotide in Plasma
Prachi Anand, Michael Koleto, Dilipkumar Reddy Kandula, Lei Xiong, Robert MacNeill
Abstract
Aim: In the theme of quantitative LC–MS bioanalysis of oligonucleotides free of ion-pairing, a 22-mer RNA oligonucleotide took center stage. The focus was on a unique polar-based retention scheme to produce a high-recovery extraction presenting a high-performance alternative extraction means, also there was the opportunity to involve hydrophilic-interaction liquid chromatography and contemporary high-resolution MS as the end point. Results: Original LC–MS methodology was developed for the oligonucleotide and the performance was robust for both nominal and accurate mass detection, the latter affording 10× improvement in sensitivity and 4000-fold linear dynamic range, 500 pM to 2000 nM. Conclusion: A novel means of solid-phase extraction is exhibited within a robust pair-free methodology, reaching pM sensitivity with the demonstrably beneficial accurate mass platform.