title: Nonaqueous electrochromatography on C30 columns: separation of retinyl esters.
abstract: A nonaqueous packed capillary electrochromatographic reversed-phase method for separation of retinyl esters has been developed. The retinyl esters all-trans-retinyl acetate, palmitate, heptadecanoate, stearate, oleoate, and linoleoate were separated on a 180 microm ID column packed with 5 microm C30 particles with a mobile phase consisting of 2.5 mM lithium acetate in N,N-dimethylformamide-methanol (99:1, v/v). With this mobile phase, the electroosmotic flow was 0.8 mm/s at 650 V/cm and 40 degrees C, and the separation was completed in less than 30 min on 30 cm columns. To obtain electrostable frits of the hydrophobic C30 material both the preparation of the frits and the conditioning of the column prior to electroconditioning were of importance. Selectivity changes were introduced by replacing up to 70% v/v of the N,N-dimethylformamide by acetonitrile. The increase in the amount of acetonitrile was, however, accompanied by a significant increase in analysis time. Liver extracts obtained from arctic seal were analyzed.
authors.affiliation: Department of Chemistry, University of Oslo, Norway. line.roed@kjemi.uio.no
authors.forename: L
authors.initials: L
authors.lastname: Roed
authors.forename: E
authors.initials: E
authors.lastname: Lundanes
authors.forename: T
authors.initials: T
authors.lastname: Greibrokk
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004224:Diterpenes; D004553:Electric Conductivity; D019075:Electrophoresis, Capillary / Q000379:methods*; D008099:Liver / Q000737:chemistry; D000084562:Retinyl Esters; D046048:Seals, Earless; D013696:Temperature; D014801:Vitamin A / Q000031:analogs & derivatives* / Q000302:isolation & purification
chemical_list: D004224:Diterpenes; D000084562:Retinyl Esters; D014801:Vitamin A; C014794:retinol palmitate; C009166:retinol acetate; C042811:retinyl stearate