Fhe carbon magnetic resonance spectra of many fatty acid methyl esters with cis and trans double bonds and triple bonds at various positions and in many different combinations have been investigated. The influence of the ester group on double and triple bonds in the fatty acid chain depends strongl
Retention behaviour of unsaturated fatty acid methyl esters on porous graphitic carbon
β Scribed by Karen Gaudin; Pierre Chaminade; Arlette Baillet
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 513 KB
- Volume
- 27
- Category
- Article
- ISSN
- 1615-9306
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β¦ Synopsis
Abstract
The eluotropic strength of binary mobile phases was calculated for three homologous series of cis, trans, and cisβcis unsaturated fatty acid methyl esters (FAMEs). Binary mobile phases with chloroform, dichloromethane, or tetrahydrofuran as strong solvent and methanol or acetonitrile as weak solvent were tested. The volume fraction of strong solvent in the binary phases was between 0.3 and 0.8. Curves of eluotropic strength versus volume fraction of strong solvents showed similar trends to previously published results for saturated homologues. Correlation coefficients of the plots of eluotropic strength values for saturated versus unsaturated FAMEs were close to 1.0. Therefore these similarities validate the model of eluotropic strength previously established with saturated FAMEs as relevant for unsaturated FAMEs. The separation factors between cis and trans homologues always showed elution of the cis before the trans homologue. The difference in retention is due primarily to the geometry of the molecule. The retention is lowered more by the addition of a first carbon double bond than by the addition of a second one, independently of the mobile phase composition.
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