An assessment of the retention behaviour of polycyclic aromatic hydrocarbons on reversed phase stationary phases--thermodynamic behaviour on C18 and phenyl-type surfaces.
The thermodynamic retention behaviour of a linear series of polycyclic aromatic hydrocarbons (PAHs) was investigated on C18 and selected phenyl-type reversed-phase stationary phases, namely C18, C18 Aqua, Propyl-phenyl and Synergi polar-RP stationary phases, using methanol mobile phases. The Propyl-phenyl stationary phase, despite having the lowest surface coverage, was found to exhibit significantly larger enthalpic interactions to the other Phenyl-type phase (Synergi polar-RP) even though this had a much higher surface coverage. This indicated that stronger interactions between the PAHs and the stationary phase ligands were occurring on the Propyl-phenyl phase. Evaluation of the elution band profile of the PAHs in the aqueous methanol mobile phase revealed fairly symmetrical bands for the C18, C18 Aqua and Synergi polar-RP, but severe peak tailing on the Propyl-phenyl phase. A change in mobile phase from methanol to acetonitrile improved the peak shape of the PAHs on the Propyl-phenyl phase, leading to the assumption that unfavourable pi-pi interactions were occurring between the electron-rich PAHs and the electron-rich phenyl rings of the Propyl-phenyl phase.
Kayillo
Sindy
S
Nanoscale Organisation and Dynamics Group, University of Western Sydney, NSW 1797, Australia.
Dennis
Gary R
GR
Shalliker
R Andrew
RA
D000327:Adsorption; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D008958:Models, Molecular; D008968:Molecular Conformation; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D013816:Thermodynamics
D011084:Polycyclic Aromatic Hydrocarbons