An oligonucleotide bioanalytical LC-SRM methodology entirely liberated from ion-pairing.

Reliable quantitative LC-MS methodology has been established and validated for an oligonucleotide in plasma in a fresh and unique fashion, free of ion-pairing reagents and the various associated deleterious effects from primary solution preparation through sample preparation and extraction to the LC-MS analytical end point, offering a highly selective mixed-mode solid-phase extraction with hydrophilic-interaction liquid chromatography as the chromatographic element prior to SRM detection. Inter- and intra-assay accuracy and precision ranged from 97.9 to 111% and 2.