title: Determination of counter-ions in synthetic peptides by ion chromatography, capillary isotachophoresis and capillary electrophoresis.
abstract: The utility of three various analytical techniques [ion chromatography (IC), capillary electrophoresis (CE) and isotachophoresis (ITP)] was tested in the determination of counter-ions in synthetic peptides. The analyzed ions were acetates, trifluoroacetates and chlorides. IC provided the best results; CE, except limit of detection and limit of quantification, exhibited the comparable results. ITP was classified as the less useful because of the problem with the determination of the chloride ions. Nevertheless, all the three techniques were able to analyze trifluoroacetates and acetates ions with satisfactory results. Except analytical methods, three procedures using hydrochloric acid (HCl) (at two different concentrations) and acetic acid as sample solvents processed by lyophilization were tested. It has been found that the lyophilization not only by HCl but also by acetic acid is a simple and cheap procedure for removal of toxic trifluoroacetic counter-ions from peptides on satisfactory levels.
authors.affiliation: Department of Inorganic Chemistry, Faculty of Pharmacy, Medical University of Gdansk, al. Hallera 107, 80-416, Gdansk, Poland. wojmrozik@gumed.edu.pl
authors.forename: Wojciech
authors.initials: W
authors.lastname: Mrozik
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Markowska
authors.forename: Lukasz
authors.initials: L
authors.lastname: Guzik
authors.forename: Bartłomiej
authors.initials: B
authors.lastname: Kraska
authors.forename: Wojciech
authors.initials: W
authors.lastname: Kamysz
mesh_terms: D000085:Acetates; D002623:Chemistry Techniques, Analytical; D002712:Chlorides; D002845:Chromatography; D019075:Electrophoresis, Capillary; D005612:Freeze Drying; D007477:Ions / Q000032:analysis*; D057625:Isotachophoresis; D010455:Peptides / Q000032:analysis* / Q000138:chemical synthesis; D014269:Trifluoroacetic Acid
chemical_list: D000085:Acetates; D002712:Chlorides; D007477:Ions; D010455:Peptides; D014269:Trifluoroacetic Acid