Influence of solvent effects on retention for a porous polymer sorbent in reversed phase liquid chromatography

Abstract

SummaryThe influence of acetonitrile, methanol and isopropanol as retention selectivity modifiers in reversed phase liquid chromatography on a poly(styrene-divinylbenzene) macroporous polymer sorbent (PLRP-S) is evaluated using the solvation parameter model. Retention results from a combination of adsorption and partitioning and is influenced by the equilibrium absorption of organic solvent by the polymer from the mobile phase. The sorption of solutes is dominated by the ease of cavity formation in or on the solvated sorbent, with a small contribution from lone pair-lone pair electron interactions. All polar interactions, such as dipole-type and hydrogenbond formation, are more favorable in the mobile phase and reduce retention. Changes in the uptake of organic solvent from the mobile phase affect kinetic properties of the column such as band broadening and porosity as well as retention. The PLRP-S solvated sorbent is suitable for solid-phase extraction and is more retentive than typical silica-based, bonded phase sorbents for extraction from water. As a surrogate system for estimating solute lipophilicity and biological activity through retention-property correlations it provides a poor fit for hydrogen-bond acid solutes and is too dipolar/polarizable to fit some models.

Investigation of the properties of hypercrosslinked polystyrene as a stationary phase for high-performance liquid chromatography

“…As mentioned above, all polymer adsorbents are to some extent solvent-sensitive; this affects both the pore size of the adsorbent and the column back pressure [22]. Hypercrosslinked polystyrene is, however, distinguished by a peculiar property of swelling independent of the thermodynamic affinity of the solvents for polystyrene [10].…”

“…It is well known that the porous structure of PS-DVB adsorbents has a great influence on their chromatographic properties : separation mechanism, retention of solutes, selectivity of separation, and column performance [22,25]. Although nitrogen adsorption measurements reveal the presence both of 100-nm diameter macropores and 1-3-nm diameter micropores in dry MN-200 [10], the pore size in the swollen polymer under the conditions used for HPLC could be different.…”

A General Model for the Optimization of Sample Processing Conditions by Solid‐Phase Extraction Applied to the Isolation of Estrogens from Urine

“…The solute descriptors used in the solvation parameter model were taken from several sources and are compiled in Table 1 [21,26,29,31]. System maps and associated calculations were preformed using a spreadsheet program Excel v.4.0 (Microsoft, Redmond, WA, USA) or Cricket Graph III (Computer Associates International, Islandia, NY, USA) on a Power Macintosh 7200 personal computer (Apple Computer, Cupertino, CA, USA).…”

“…(1). System maps for a butylsiloxane-bonded [28], a cyanopropylsiloxane-bonded [29] and a spacer bonded propanediol [30] silica sorbent, for a macroreticular porous polymer [31][32][33], and a limited range of values for carbon [34], are available for several aqueous-organic solvent mixtures. These maps provide the limited basis for sorbent selection at present.…”

Application of solvation model to prediction of the solute retention in liquid chromatography over a wide range of mobile-phase compositions

“…(1) describe the properties of the separation system; they are defined as the difference in the properties of the stationary and mobile phases [14][15][16][17][18][19][20][21][22]. Coefficient v is determined by the cohesive energy of the mobile and stationary phases and reflects the effect of dispersive interactions.…”