title: Hydrophilic interaction electrokinetic chromatography using bio-based nanofillers.
abstract: Hydrophilic interaction (HI)-based separation like HILIC is effective for analyzing hydrophilic biological samples such as carbohydrates, peptides, and metabolites. To overcome the drawbacks of conventional HILIC such as large consumption of organic solvents and easy deterioration of the separation column, we developed HI electrokinetic chromatography (EKC) by employing bio-based nanomaterials as the hydrophilic pseudostationary phase. By mechanical/chemical treatments, cellulose, chitin, and chitosan were processed to 10-nm wide nanofibers/nanowhiskers (NFs/NWs), which are longer/shorter than 1000/200 nm, respectively. In HI-EKC of oligosaccharides using 0.001% uncharged cellulose NFs, strong interaction was observed for the large-size oligosaccharides with the retention factors (k) of up to 1.56, indicating a HILIC-mode interaction. In HI-EKC with 0.1% positively charged chitosan NFs, benzenedisulfonic acid, benzenesulfonic acid (BS), and p-hydroxy BS (HBS) had k values of 0.036, 0.018, and 0.018, respectively, suggesting that the ion-exchange interaction mainly occurred via sulfonate groups. Finally, HI-EKC was demonstrated using 0.05% chitin or chitosan NWs. In both cases using chitin and chitosan NWs, HBS showed much stronger interaction with k > 0.192 compared with BS with k < 0.070. It indicated structural difference between NFs and NWs affected the HI behavior in terms of both the ion-exchange and HILIC modes.
authors.affiliation: Health Research Institute, National Institute of Advanced Industrial Science and Technology, Midorigaoka, Ikeda, Osaka, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kawai
authors.forename: Masato
authors.initials: M
authors.lastname: Watanabe
authors.forename: Kojiro
authors.initials: K
authors.lastname: Uetani
authors.forename: Yudai
authors.initials: Y
authors.lastname: Fukushima
authors.forename: Kenji
authors.initials: K
authors.lastname: Sueyoshi
authors.forename: Takuya
authors.initials: T
authors.lastname: Kubo
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Kitagawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yano
authors.forename: Koji
authors.initials: K
authors.lastname: Otsuka
mesh_terms: D000476:Alkanesulfonates / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry; D002686:Chitin / Q000737:chemistry; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D019075:Electrophoresis, Capillary; D057927:Hydrophobic and Hydrophilic Interactions; D049329:Nanostructures / Q000737:chemistry*; D009844:Oligosaccharides / Q000737:chemistry*; D013451:Sulfonic Acids / Q000737:chemistry
chemical_list: D000476:Alkanesulfonates; D009844:Oligosaccharides; D013451:Sulfonic Acids; D002686:Chitin; D002482:Cellulose
keywords: Bio-based nanomaterials; Capillary electrophoresis; Electrokinetic chromatography; Hydrophilic interaction