title: Stepwise gradient of buffer concentration for capillary electrochromatography of peptides on sulfonated naphthalimido-modified silyl silica gel.
abstract: The advantage of using a stepwise gradient of buffer concentration in CEC was demonstrated with the mixed-mode stationary phase, 3-(4-sulfo-1,8-naphthalimido)propyl-modified silyl silica gel (SNAIP). Before the application of a stepwise gradient, the effect of buffer concentration on the separations of six peptides and tryptic digests was investigated. Bubble formation caused by Joule heating at currents up to 95 microA was successfully suppressed by using SNAIP column even without pressurization, which contributed to a stepwise gradient of buffer concentration. Utilizing the stepwise gradient improved and shortened the separation of six peptides as compared to the separation under an isocratic elution.
authors.affiliation: Graduate School of Biomedical Sciences, Course of Pharmaceutical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
authors.forename: Kaname
authors.initials: K
authors.lastname: Ohyama
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Wada
authors.forename: Naoya
authors.initials: N
authors.lastname: Kishikawa
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Ohba
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Nakashima
authors.forename: Naotaka
authors.initials: N
authors.lastname: Kuroda
mesh_terms: D002021:Buffers; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D002021:Buffers; D058428:Silica Gel; D012822:Silicon Dioxide