Postpolymerization modification of a hydroxy monolith precursor. Part II. Epoxy biphenyl modified poly (hydroxyethyl methacrylate-co-pentaerythritol triacrylate) monolithic capillary columns for reversed-phase capillary electrochromatography based on π-π and hydrophobic interactions.
In this second part of the series of investigations involving the postpolymerization modification of a hydroxy monolith (OHM) capillary column, the surface hydroxyl groups were reacted with epoxy biphenyl thus yielding the so-called Biphenyl OHM capillary column. The modification involved the epoxy ring opening of the 2-biphenylyl glycidyl ether catalyzed by BF3and its subsequent reaction with the hydroxyl groups on the OHM precursor surface. The Biphenyl OHM capillary column thus obtained exhibited the typical reversed phase behavior by primarily hydrophobic interactions vis-à-vis the homologous series of alkyl benzenes and in addition by π-π interactions toward nitroalkane homologous series via their π-electron rich nitro groups. This dual retention mechanism was very distinctly observed with a set of PAH solutes in the sense that the k values of the PAH solutes were comparable to those obtained on a more non polar stationary phase, namely the Epoxy OHM C-16 reported in the preceding article. Other aromatic solutes showed the dual retention mechanism on the Biphenyl OHM capillary including phenols, anilines derivatives, and phenoxy acid herbicides. The Biphenyl OHM capillary exhibited good reproducibility from run-to-run, day-to-day, and column-to-column.
Department of Chemistry, Oklahoma State University, Stillwater, OK, USA.
Shantipriya
S
Khadka
Department of Chemistry, Oklahoma State University, Stillwater, OK, USA.
Ziad
Z
El Rassi
D000179:Acrylates / Q000737:chemistry*; D000814:Aniline Compounds / Q000032:analysis / Q000737:chemistry; D001713:Biphenyl Compounds / Q000737:chemistry*; D053801:Capillary Electrochromatography / Q000295:instrumentation*; D056148:Chromatography, Reverse-Phase / Q000295:instrumentation*; D004852:Epoxy Compounds / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D010636:Phenols / Q000032:analysis / Q000737:chemistry; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000737:chemistry; D011102:Polyhydroxyethyl Methacrylate / Q000737:chemistry*; D011409:Propylene Glycols / Q000737:chemistry*; D015203:Reproducibility of Results
D000179:Acrylates; D000814:Aniline Compounds; D001713:Biphenyl Compounds; D004852:Epoxy Compounds; D010636:Phenols; D011084:Polycyclic Aromatic Hydrocarbons; D011102:Polyhydroxyethyl Methacrylate; D011409:Propylene Glycols; C010574:biphenyl; C027992:pentaerythrityl triacrylate
Aromatic compounds; Biphenyl monolithic column; Capillary electrochromatography; Monolithic precursor column; Postpolymerization modification