- 著者
- Nobuyuki TAKAYAMA Lee Wah LIM Toyohide TAKEUCHI
- 出版者
- (社)日本分析化学会
- 雑誌
- Analytical Sciences (ISSN:09106340)
- 巻号頁・発行日
- vol.33, no.5, pp.619-625, 2017-05-10 (Released:2017-05-10)
- 参考文献数
- 24
- 被引用文献数
- 12
The retention behavior of inorganic anions was studied in hydrophilic interaction chromatography (HILIC). In this study, five kinds of HILIC stationary phases (amino, imidazole, amide, pyridine and zwitterionic) were investigated. It was found that only amino and imidazole columns exhibited the separation of inorganic anions under HILIC conditions. The retention mechanism was further investigated under both columns. A reversed elution order of inorganic anions was observed under the HILIC condition compared with those observed under the ion-exchange chromatography mode (IEC). The effect of salt species and their concentration in the eluent were investigated under constant acetonitrile (ACN) content. Sodium chloride and sodium perchlorate were chosen as the salt, and the salt (sodium perchlorate) concentration was varied from 10 to 40 mM to confirm the effect of the electrostatic interaction. The slope values of the plots of the log retention factor (k) versus the log eluent concentration were calculated to be between –0.43 and –0.45 for the amino column, while those obtained on the imidazole column were between –0.68 and –0.73. Various concentrations of ACN were also examined with 20 mM sodium perchlorate, and the typical HILIC retention behavior was observed on both amino and imidazole columns. Due to the obtained results, it is considered that the separation of inorganic anions under the HILIC condition was achieved by both electrostatic interaction and partition.
- 著者
- Nobuyuki TAKAYAMA Lee Wah LIM Toyohide TAKEUCHI
- 出版者
- (社)日本分析化学会
- 雑誌
- Analytical Sciences (ISSN:09106340)
- 巻号頁・発行日
- vol.33, no.5, pp.631-634, 2017-05-10 (Released:2017-05-10)
- 参考文献数
- 19
- 被引用文献数
- 2
Zwitterionic monolithic columns were synthesized by a one-pot reaction using [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide, ethylene dimethacrylate, methanol and 2,2′-azobis(isobutyronitrile) as the monomer, cross-linker, porogen and initiator, respectively. The optimum conditions for polymerization and the efficiency of the prepared columns were examined for ion chromatography. The separation of five kinds of inorganic anions was achieved. The back pressures were monitored as increasing flow-rate, and the resulting plate heights (i.e. height equivalent of a theoretical plate, HETP) of SCN− were calculated at the inspected flow-rates. It was found that the increment rates of both the back pressure and HETP were rather slight. Mobile phases containing various cations or acid increased the retention times of the anions. Divalent cations could be separated, while monovalent cations could not be resolved due to their weak retention on the stationary phases.