Ion-exclusion chromatography with conductimetric detection of aliphatic carboxylic acids on a weakly acidic cation-exchange resin by elution with benzoic acid-beta-cyclodextrin.
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.
Tanaka
Kazuhiko
K
National Institute of Advanced Industrial Science and Technology, 110 Nishiibara-cho, Seto, Aichi 489-0884, Japan. kazuhiko-tanaka@aist.go.jp
Mori
Masanobu
M
Xu
Qun
Q
Helaleh
Murad I H
MI
Ikedo
Mikaru
M
Taoda
Hiroshi
H
Hu
Wenzhi
W
Hasebe
Kiyoshi
K
Fritz
James S
JS
Haddad
Paul R
PR
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
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