Peptide separation in hydrophilic interaction capillary electrochromatography.
Separation of small peptides by hydrophilic interaction capillary electrochromatography (HI-CEC) has been investigated. The negative surface charge of a hydrophilic, strong-cation-exchange stationary phase (PolySULFOETHYL A) provided a substantial cathodic electroosmotic flow (EOF). The influence of acetonitrile content, ionic strength, mobile phase pH as well as applied voltage on the migration of the peptides was studied. Possible retention mechanisms of the peptides in HI-CEC were discussed. It was found that hydrophilic interaction between the solutes and the stationary phase played a major role in this system, especially when mobile phases with high acetonitrile content were used. However, an ion-exchange mechanism and electrophoretic mobility also affect the migration of the peptides in HI-CEC. Elution order and selectivity was proved to be different in HI-CEC and capillary zone electrophoresis (CZE), thus revealing the potential of HI-CEC as a complementary technique to CZE for the separation of peptides. Efficiency and selectivity of HI-CEC for the separation of peptides were demonstrated by baseline separating nine peptides in 6 min.
Fu
Hongjing
H
National Chromatographic R&A Center, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, China.
Jin
Wenhai
W
National Chromatographic R&A Center, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, China.
Xiao
Hua
H
National Chromatographic R&A Center, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, China.
Huang
Haiwei
H
National Chromatographic R&A Center, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, China.
Zou
Hanfa
H
National Chromatographic R&A Center, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, China.
D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D009994:Osmolar Concentration; D010455:Peptides / Q000302:isolation & purification*
D010455:Peptides