title: Peak shape improvement of basic analytes in capillary liquid chromatography.
abstract: The analysis of bases is of special interest in pharmaceutical research because numerous active substances contain basic functional groups. Capillary and conventional size LC separations of drug substances spiked with potential impurities were compared. In the case of the nonpolar drug levonorgestrel equal separation efficiency was readily attained by both techniques. The peaks of basic substances, however, showed extensive tailing when separated by capillary LC. The peak deformation was attributable to interactions of the basic substances with the polar inner surface of the fused silica capillaries employed in capillary LC and does not appear with the steel tubing generally used in conventional size LC. This drawback of capillary LC was overcome by use of deactivated fused silica capillaries for column hardware and transfer lines.
authors.affiliation: Schering AG, Analytical Development 3, Müllerstr. 178, D-13342 Berlin, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Prüss
authors.forename: Christine
authors.initials: C
authors.lastname: Kempter
authors.forename: Jens
authors.initials: J
authors.lastname: Gysler
authors.forename: Jürgen
authors.initials: J
authors.lastname: Maier-Rosenkranz
authors.forename: Thomas
authors.initials: T
authors.lastname: Jira
mesh_terms: D000639:Amitriptyline / Q000737:chemistry; D001549:Benzamides / Q000737:chemistry; D002853:Chromatography, Liquid / Q000379:methods*; D016912:Levonorgestrel / Q000737:chemistry; D015394:Molecular Structure; D011725:Pyridines / Q000737:chemistry
chemical_list: D001549:Benzamides; D011725:Pyridines; D000639:Amitriptyline; C118739:entinostat; D016912:Levonorgestrel