The influence of the mobile phase pH and the stationary phase type on the selectivity tuning in high performance liquid chromatography nucleosides separation

Abstract

Analysis of the modified nucleosides is particularly important in the medical area because of a possibility of cancerogenic processes studies. The aim of this work was to study the selectivity tuning of modified nucleosides through the investigations of interactions analyte (modified nucleoside) <==> stationary phase <==> mobile phase. A series of homemade stationary phases with different surface properties has been utilized. All of them contain various interaction sites such as: cholesterol (SG-CHOL); n-acylamide (SG-CHOL, SG-AP); aminopropyl (SG-CHOL, SG-AP, SG-NH2, SG-MIX); cyanopropyl, phenyl, octyl (SG-MIX), octadecyl (SG-MIX, SG-C18) and silanols localized on the silica gel surface of all packings. The attempt to predict the main interactions responsible for the retention between nucleosides and stationary phase ligands was done on the basis of the elemental analysis, and proportional part of an individual ligand bonded to silica surface results. In order to study the influence of different packing types on the analyzed nucleosides retention, the relationship between pH of the mobile phase buffer and the selectivity of a stationary phase was investigated.

Stationary phase characterization and method development

“…Kowalska et al [196] varied mobile phase pH and stationary phase type for the development of a method for nucleosides. The stationary phases were complex, carryi 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.jss-journal.com ing charges, and polar functional groups besides the hydrophobic ligand.…”

A new way to fast and high resolution determination of modified nucleosides

“…Capillary electrophoresis allows to obtain high sensitivity in case of nucleosides [4,13,17,18], however it was almost completely replaced by reversed phase high performance liquid chromatography (RP HPLC) [17,18]. It becomes the preferred method for the analysis of the board range of modified nucleosides [5,13,[19][20][21]. HPLC gives precise quantification of nucleosides; moreover this technique is fast, simple and the cost of analysis is relatively low.…”

“…Only one type of column is used in the chromatographic analysis of nucleosides in almost all cases, namely octadecyl C 18 stationary phase. Some attempts to apply more specific stationary phases in the analysis of these group of compounds were done; however they were not commonly used [21,22]. RP HPLC using organic solvent and buffer as the eluents were mainly applied to the separation of a number of nucleosides.…”

Preparation and evaluation of hydrophilic C18 monolithic sorbents for enhanced polar compound retention in liquid chromatography and solid phase extraction

“…The classical RP phases include silica-based alkyl (C4, C8, C18), carbons or polymeric poly(styrene-divinylbenzene) (PS-DVB), which are hydrophobic and retain non-polar analytes effectively. However, for polar analytes, these nonpolar phases showed limited extent of retention in RP mode, especially under highly aqueous conditions [1,2]. This problem has been addressed by using aqueous (AQ) type RP stationary phases (silica-based) in LC and hydrophilic polymer sorbents in SPE [3][4][5][6][7][8].…”