Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2001-9-5
pubmed:abstractText
The solvation parameter model is used to study the retention mechanism of neutral organic compounds on porous graphitic carbon with methanol-water mobile phases containing from 0-100% (v/v) methanol. The dominant contribution to retention is the cavity formation-dispersion interaction term, composed of favorable interactions in the mobile phase (hydrophobic effect) and additional contributions from adsorption on the graphite surface. Electron lone pair and dipole-type interactions in the adsorbed state result in increased retention. Hydrogen-bonding interactions are more favorable in the mobile phase resulting in lower retention. The changes in the system constants of the solvation parameter model for cavity formation-dispersion interactions and hydrogen-bond interactions are linearly related to the volume fraction of water in the mobile phase. The system constants for electron lone pair interactions and dipole-type interactions are non-linear and go through a maximum and minimum value, respectively, at a specific mobile phase composition. The solvation parameter model poorly predicts the retention properties of angular molecules. This is probably due to the failure of the characteristic volume to correctly model the contact surface area for the interaction of angular molecules with the planar graphite surface. General factors affecting the quality of model fits for adsorbents are discussed.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Aug
pubmed:issn
0003-2654
pubmed:author
pubmed:issnType
Print
pubmed:volume
126
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1318-25
pubmed:dateRevised
2003-10-31
pubmed:year
2001
pubmed:articleTitle
Retention characteristics of porous graphitic carbon in reversed-phase liquid chromatography with methanol-water mobile phases.
pubmed:affiliation
Department of Chemistry, Wayne State University, Detroit, MI 48202, USA.
pubmed:publicationType
Journal Article