Retention divergence of terpenes with porous graphitized carbon and C18 stationary phases.
The significant divergence between the retention of 16 terpene standards on porous graphitized carbon (PGC) and C₁₈ packing materials are illustrated. The PGC surface is shown to provide a selectivity toward shape, polarity, and structure that is not afforded by the C₁₈ surface. This observation is illustrated by plots of the retention factors similar to those typically used to represent 2D-HPLC separations. A geometric approach to factor analysis was used to measure the separation divergence together with the selectivity and the product selectivity factors of closely related species. When a methanol mobile phase was used with the PGC surface, a large fraction of the separation space could be utilized. That is further reflected by a spreading angle of 80.3°. The PGC material was also successful at resolving structural isomers where the C₁₈ phase was not. It was also found that the choice of the mobile phase is important when using this material. A much larger degree of space utilization was seen with methanol than with acetonitrile that displayed a spreading angle of only 40.8°.
Department of Chemistry, University of Tennessee, Knoxville, TN, USA.
Paul G
PG
Stevenson
Georges
G
Guiochon
D000097:Acetonitriles / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation* / Q000379:methods; D006108:Graphite / Q000737:chemistry*; D006838:Hydrocarbons / Q000737:chemistry; D000432:Methanol / Q000737:chemistry; D008958:Models, Molecular; D016062:Porosity; D013729:Terpenes / Q000737:chemistry* / Q000302:isolation & purification
D000097:Acetonitriles; D006838:Hydrocarbons; D013729:Terpenes; D006108:Graphite; D000432:Methanol; C032159:acetonitrile