title: Two-step ion-exchange chromatographic purification combined with reversed-phase chromatography to isolate C-peptide for mass spectrometric analysis.
abstract: A liquid chromatography with mass spectrometry on-line platform that includes the orthogonal techniques of ion exchange and reversed phase chromatography is applied for C-peptide analysis. Additional improvement is achieved by the subsequent application of cation- and anion-exchange purification steps that allow for isolating components that have their isoelectric points in a narrow pH range before final reversed-phase mass spectrometry analysis. The utility of this approach for isolating fractions in the desired "pI window" for profiling complex mixtures is discussed.
authors.affiliation: University of Missouri, School of Medicine, One Hospital Drive, Columbia, MO, USA.
authors.forename: Kuanysh
authors.initials: K
authors.lastname: Kabytaev
authors.affiliation: University of Missouri, School of Medicine, One Hospital Drive, Columbia, MO, USA.
authors.forename: Anita
authors.initials: A
authors.lastname: Durairaj
authors.affiliation: University of Missouri, School of Medicine, One Hospital Drive, Columbia, MO, USA.
authors.forename: Dmitriy
authors.initials: D
authors.lastname: Shin
authors.affiliation: University of Missouri, School of Medicine, One Hospital Drive, Columbia, MO, USA.
authors.forename: Curt L
authors.initials: CL
authors.lastname: Rohlfing
authors.affiliation: University of Missouri, School of Medicine, One Hospital Drive, Columbia, MO, USA.
authors.forename: Shawn
authors.initials: S
authors.lastname: Connolly
authors.affiliation: University of Missouri, School of Medicine, One Hospital Drive, Columbia, MO, USA.
authors.forename: Randie R
authors.initials: RR
authors.lastname: Little
authors.affiliation: University of Missouri, School of Medicine, One Hospital Drive, Columbia, MO, USA.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Stoyanov
mesh_terms: D000838:Anions; D002096:C-Peptide / Q000737:chemistry* / Q000302:isolation & purification*; D002412:Cations; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002852:Chromatography, Ion Exchange / Q000379:methods*; D002853:Chromatography, Liquid; D056148:Chromatography, Reverse-Phase / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D013058:Mass Spectrometry / Q000379:methods*; D010949:Plasma / Q000737:chemistry
chemical_list: D000838:Anions; D002096:C-Peptide; D002412:Cations
keywords: C-peptide; Ion exchange chromatography; Isotope dilution assay; Orthogonal separations; Peptide purification