title: Effect of the temperature and mobile phase composition on the retention behavior of nitroanilines on ligand-exchange stationary phase.
abstract: This paper deals with the separation of isomers of nitroaniline by liquid chromatography using the ligand-exchange technique. The chromatographic separations were performed on the ligand-exchanger sporopollenin. The sporopollenin used as support of stationary phase was modified with carboxylated-ethylenediamine matrix and was loaded with cobalt(II) ions. Using the column packed with cobalt(II) loaded carboxylated diaminoethyl sporopollenin [Co(II)-CDAE-S], the retention behavior of 3- and 4-nitroanilines was investigated. The mobile phase used, was a mixture of 0.05 M NH(4)OH in ethanol-water. The resolution was strongly affected by the presence of ammonium hydroxide in the mobile phase and a concentration of 0.05 M was shown to be necessary for the separation of analytes. To study the effects of temperature on the resolution, column runs were also performed at various temperatures (15-60 degrees C). With increasing temperature, a decreased interaction between the solutes and the ligand-exchanger was observed. Consequently, the best results were obtained using a mixture of 0.05 M NH(4)OH in ethanol-water (10:90, v/v) as the mobile phase at a column temperature of 35 degrees C. Ligand-exchange chromatography on the Co(II)-CDAE-S could be a useful alternative method for the separation of nitroaniline.
authors.affiliation: Department of Chemistry, Faculty of Sciences and Arts, Niğde University, Niğde, Turkey.
authors.forename: A Ali
authors.initials: AA
authors.lastname: Gürten
authors.forename: Mustafa
authors.initials: M
authors.lastname: Uçan
authors.forename: Meysun I
authors.initials: MI
authors.lastname: Abdullah
authors.forename: Ahmet
authors.initials: A
authors.lastname: Ayar
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D001704:Biopolymers / Q000737:chemistry; D002338:Carotenoids / Q000737:chemistry; D002853:Chromatography, Liquid; D008024:Ligands; D015394:Molecular Structure; D013696:Temperature
chemical_list: D000814:Aniline Compounds; D001704:Biopolymers; D008024:Ligands; C009800:sporopollenin; C008625:nitroaniline; D002338:Carotenoids