title: Ion-exclusion chromatography with conductimetric detection of aliphatic carboxylic acids on a weakly acidic cation-exchange resin by elution with benzoic acid-beta-cyclodextrin.
abstract: In this study, an aqueous solution consisting of benzoic acid with low background conductivity and beta-cyclodextrin (beta-CD) of hydrophilic nature and the inclusion effect to benzoic acid were used as eluent for the ion-exclusion chromatographic separation of aliphatic carboxylic acids with different pKa values and hydrophobicity on a polymethacrylate-based weakly acidic cation-exchange resin in the H+ form. With increasing concentration of beta-cyclodextrin in the eluent, the retention times of the carboxylic acids decreased due to the increased hydrophilicity of the polymethacrylate-based cation-exchange resin surface from the adsorption of OH groups of beta-cyclodextrin. Moreover, the eluent background conductivity decreased with increasing concentration of beta-cyclodextrin in 1 mM benzoic acid, which could result in higher sensitivity for conductimetric detection. The ion-exclusion chromatographic separation of carboxylic acids with high resolution and sensitivity was accomplished successfully by elution with a 1 mM benzoic acid-10 mM cyclodextrin solution without chemical suppression.
authors.affiliation: National Institute of Advanced Industrial Science and Technology, 110 Nishiibara-cho, Seto, Aichi 489-0884, Japan. kazuhiko-tanaka@aist.go.jp
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Tanaka
authors.forename: Masanobu
authors.initials: M
authors.lastname: Mori
authors.forename: Qun
authors.initials: Q
authors.lastname: Xu
authors.forename: Murad I H
authors.initials: MI
authors.lastname: Helaleh
authors.forename: Mikaru
authors.initials: M
authors.lastname: Ikedo
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Taoda
authors.forename: Wenzhi
authors.initials: W
authors.lastname: Hu
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Hasebe
authors.forename: James S
authors.initials: JS
authors.lastname: Fritz
authors.forename: Paul R
authors.initials: PR
authors.lastname: Haddad
mesh_terms: D000327:Adsorption; D019817:Benzoic Acid; D002138:Calibration; D002264:Carboxylic Acids / Q000032:analysis*; D002411:Cation Exchange Resins; D002852:Chromatography, Ion Exchange / Q000379:methods*; D003505:Cyclodextrins; D004553:Electric Conductivity; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D000432:Methanol; D011109:Polymethacrylic Acids; D011786:Quality Control; D012680:Sensitivity and Specificity; D012996:Solutions; D047392:beta-Cyclodextrins
chemical_list: D002264:Carboxylic Acids; D002411:Cation Exchange Resins; D003505:Cyclodextrins; D007202:Indicators and Reagents; D011109:Polymethacrylic Acids; D012996:Solutions; D047392:beta-Cyclodextrins; C030613:polymethacrylic acid; D019817:Benzoic Acid; C031215:betadex; D000432:Methanol