title: Application of a cholesterol stationary phase in the analysis of phosphorothioate oligonucleotides by means of ion pair chromatography coupled with tandem mass spectrometry.
abstract: The main aim of this study was the investigation of the influence of several ion pair reagents towards both the retention and the mass spectrometry sensitivity of phosphorothioate oligonucleotides. A cholesterol stationary phase was applied for the first time in the analysis of this group of compounds. The mobile phase composition was modified by changing the concentration and the type of amines and acetates or 1,1,1,3,3,3-hexafluoroisopropanol. It has been shown that the increase of amines concentration results in the retention factor increase for each oligonucleotide, on each adsorbent. The only exception was the mobile phase composed of triethylamine and 1,1,1,3,3,3-hexafluoroisopropanol. This is a consequence of interactions taking place between a cholesterol molecule and an alcohol. This effect was convenient when the mass spectrometry detection was applied, since it allowed an increase in the sensitivity. Moreover, optimization of the mobile phase composition and its impact on the efficiency of ionization process and on the sensitivity in mass spectrometry were also presented. The optimization of this new method, based on cholesterol stationary phase coupled with mass spectrometry detection, was finally applied for the determination of phosphorothioate oligonucleotides impurity in a real sample.
authors.affiliation: Chair of the Environmental Chemistry & Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarin St., PL-87 100, Poland. Electronic address: kowalska@chem.umk.pl.
authors.forename: Sylwia
authors.initials: S
authors.lastname: Studzińska
authors.affiliation: Chair of the Environmental Chemistry & Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarin St., PL-87 100, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Krzemińska
authors.affiliation: Chair of the Environmental Chemistry & Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarin St., PL-87 100, Poland.
authors.forename: Michał
authors.initials: M
authors.lastname: Szumski
authors.affiliation: Chair of the Environmental Chemistry & Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarin St., PL-87 100, Poland.
authors.forename: Bogusław
authors.initials: B
authors.lastname: Buszewski
mesh_terms: D002784:Cholesterol; D002845:Chromatography; D009841:Oligonucleotides; D054735:Phosphorothioate Oligonucleotides; D020005:Propanols; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D006845:Hydrocarbons, Fluorinated
chemical_list: D002784:Cholesterol; D009841:Oligonucleotides; D054735:Phosphorothioate Oligonucleotides; D020005:Propanols; C001337:hexafluoroisopropanol; D006845:Hydrocarbons, Fluorinated
keywords: Cholesterol stationary phase; Fragmentation; Ion pair chromatography; Ion pair reagents; Mass spectrometry; phosphorothioate oligonucleotides