title: Sensitivity enhancement of CE and CE-MS for the analysis of peptides by a dynamic pH junction.
abstract: An analytical method of CE-MS and CE with an online preconcentration technique induced by a dynamic pH junction, addition of organic solvent and large volume injection was developed for sensitive determination of peptides in biological samples. Leucine enkephalin, methionine enkephalin, dynorphin A, β-endorphin and angiotensin II were used as model peptides. The optimal online preconcentration conditions were obtained at a sample matrix consisting of 100 mM borate buffer (pH 10.0) with 50% v/v acetonitrile and a BGE containing 1 M formic acid at pH 2.0, along with a 25-cm injection length. Under the optimized conditions, a 4.0×10(3)-1.1×10(4)-fold increase in peak intensity was achieved without degrading the peak shape. This online preconcentration method was applied to analyze the intracellular angiotensin II within the peptides extracted from HL1 cells and approximately increase of 1×10(4)-fold sensitivity was achieved compared to normal condition. Thus, the developed method could be applied to the analysis of various peptides for peptidomics study in biological samples.
authors.affiliation: Integrated Omics Center, Life/Health Division, Korea Institute of Science and Technology, Seoul, Republic of Korea.
authors.forename: Md Nabiul
authors.initials: MN
authors.lastname: Hasan
authors.forename: Soo Hyun
authors.initials: SH
authors.lastname: Park
authors.forename: Eulsik
authors.initials: E
authors.lastname: Oh
authors.forename: Eun Joo
authors.initials: EJ
authors.lastname: Song
authors.forename: Eunmi
authors.initials: E
authors.lastname: Ban
authors.forename: Young Sook
authors.initials: YS
authors.lastname: Yoo
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D010455:Peptides / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D010455:Peptides