Separation of Inorganic Anions on a Chemically Bonded 18-Crown-6 Ether Stationary Phase in Capillary Ion Chromatography

Development of Chemically Bonded Crown Ether Stationary Phases in Capillary Ion Chromatography

“…By comparing the result of 2AM18C6 to our previous study [12], the coverage obtained in the current study was calculated to be 1.6-fold higher (previously it was 0.24 mmol g -1 ), while those for aza-crown ethers were both relatively higher compared to those of 2AM18C6 obtained.…”

“…It should be noted that since ions are generally separated based on the difference in electrostatic interaction with the stationary phase, therefore the stationary phases should possess charges that are inherently provided or dynamically acquired. In our previous studies, we found that stationary phases that were dynamically coated [10] or chemically bonded [12] with crown ethers could separate common inorganic anions in the ion-exchange mode; the retention behavior and the elution order of the analyte anions were found to be similar to those observed as in common ion chromatographic separations. These separation results could also be observed when poly(ethylene oxide) (PEO), i.e.…”

“…The crown ether-bonded stationary phases were prepared similar to that of our previous work with some modifications on each reaction step and the second reaction solvent was optimized in this study [12]. The dried porous silica gel was firstly reacted to 3-glycidyloxypropyltrimethoxysilane (GPTMS) using dried toluene as the solvent and the reaction was carried out at 110°C for 18 h in the reaction vessel.…”

“…Based on this unique ability of crown ether to selectively complex alkali metal cations, we have used it as the basis for chromatographic separation of anions in capillary ion chromatography [10][11][12]. It should be noted that since ions are generally separated based on the difference in electrostatic interaction with the stationary phase, therefore the stationary phases should possess charges that are inherently provided or dynamically acquired.…”

Development of Micro-Flow-Controlled Techniques and Novel Stationary Phases in Capillary Liquid Chromatography

“…This model was verified by using crown ethers as the eluent additive in the reversed-phase mode [64]. By using this cation-trapping ability, chemically-bonded crown ether stationary phases were developed and the retention of both anions and cations on the same stationary phase was investigated [65][66]. Besides the retention of anions in the ion-exchange mode, by using eluent with higher pH would favor the retention and separation of the metal cations.…”