Molecular Shape Selectivity for Polycyclic Aromatic Compoundson a Poly(4-vinylpyridine) Stationary Phase in Liquid Chromatography

Abstract

Poly(4-vinylpyridine) (P4VP) was introduced as a stationary phase in liquid chromatography (LC) and the retention behavior of polycyclic aromatic compounds (PACs) on the P4VP phase has been investigated by comparing with that observed on commercially-available octadecylsilica (ODS) and phenylbutylsilica (PBS) phases. On the P4VP phase, a good linear relationship between the logarithmic retention factor and the molecular size of planar PACs was obtained, however, a unique selectivity for some planar PACs was also observed. The P4VP phase demonstrated a specific retention trend, where planar PACs having "square-like" molecular shape were strongly retained. The above trend clearly suggested a unique selectivity of the P4VP phase for PACs. In addition, compared to the typical ODS and PBS phases, the P4VP phase showed a good molecular shape recognition capability for planar/non-planar PACs with a similar two-dimensional molecular size. The P4VP phase showed a very small retention for various alkylbenzenes, suggesting somewhat limited contribution of the hydrophobicity of the analytes to the retention. In the investigation for the selectivity to structural isomers, the P4VP phase exhibited a unique selectivity for isomers of dichlorobenzene and dibromobenzene when compared to the typical ODS and PBS phases. The trend can be interpreted as a dipole-dipole interaction between pyridyl groups in the P4VP ligands and the analyte.

Fibrous Polyimide Stationary Phase for the Separation of Aromatic Compounds in Reversed-Phase Liquid Chromatography

“…Various types of synthetic polymer materials have been developed; thus, many candidates are available for the support of separation media in separation science. Introducing a polymer particle with heat and chemical resistance, a novel type of stationary phase can develop for use under conditions that is difficult to adopt for conventional silicagel-based stationary phases [35]. Synthetic polymer materials have been employed as novel extraction media for sample preparation techniques in LC [36] and gas chromatography (GC) [37,38].…”

Molecular Shape Selectivity for Polycyclic Aromatic Compounds on a Poly(benzoguanamine-<i>co</i>-melamine-<i>co</i>-formaldehyde) Stationary Phase in Reversed-Phase Liquid Chromatography

“…In fact, various types of new stationary phases have been developed in LC [9][10][11][12][13][14]. Octadecylsilica (ODS) is widely employed as a stationary phase in LC because of the several advantageous features such as a good versatility, high separation performance, and significantly wide commercial availability with a reasonable cost [15]. However, typical ODS phases still have some problems to be solved, such as insufficient heat resistance and chemical resistance, along with a limitation on the mobile phase composition.…”