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Cations on Ion Chromatography by Phosphate-Coated Zirconia Stationary Phase Column

Mori M., Masuno T., Kozaki D., Nakatani N., Tanaka K., Itabashi H.

Acta Chromatographica

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2015

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Vol. 27, no. 4

767--773

EN

Ion chromatography of inorganic cations using a phosphate-coated zirconia stationary phase (PZ) was first attempted. The retentions of cations to PZ increased by elevating the column temperature and the reproducibility of the separation could improve at the higher temperature. The PZ functioned as a cation-exchanger from changes in the retention factor of cations as a function of eluent pH. Furthermore, the Gibbs free energies of cations were estimated from enthalpy and entropy using the retention factors of cations as a function of the column temperature. The reaction was based on the endothermic reaction.

2

Effect of perfluorinated surfactant as additive of background electrolyte for capillary electrophoresis of inorganic cations

Mori M., Ikeda T., Itabashi H.

Acta Chromatographica

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2012

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Vol. 24, no. 4

529--542

EN

This study reports the effect of a nonionic perfluorinated surfactant, N-polyoxyethylene-N-propyl perfluorooctane sulfonamide (PFOSA), as additive of background electrolyte on capillary electrophoresis (CE) of common inorganic cations. The association constants (Kass) for PFOSA estimated from the electrophoretic mobility of analyte cations were the order of Mg2+ > Ca2+ > Sr2+ > K+ ≈ NH4+ > Na+ ≈ Li+. The Kass values were larger than those for zwitterionic and nonionic surfactants with hydrocarbon moiety. Use of PFOSA made another essential contribution to the determination of inorganic cations in a protein-containing sample. This was considered because high solubility of PFOSA for proteins functioned as suppressor for protein adsorption to the capillary wall. Four inorganic cations, Na+, K+, Mg2+, and Ca2+, in human saliva sample were successfully determined by sample injection without any pretreatments except for filtration and dilution.

3

Use of combined ion-exclusion and cation-exchange chromatography to study photooxidation of ionic nitrogen compounds on a titanium dioxide photocatalyst

Mori M., Taoda H., Itabashi H., Ikedo M., Tanaka K.

Acta Chromatographica

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2006

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No. 16

28-37

EN

Combined ion-exclusion and cation-exchange chromatography (IEC/CEC) on a weakly acidic cation-exchange resin in the H+-form (TSKgel Super IC-A/C) has been used as an advanced method for evaluation of the photooxidation of ionic nitrogen compounds, for example triethanolamine, trimethylamine, and urea, on a TiO2 photocatalyst. Formation of NH4+ and NO3- from each nitrogen compound by photooxidation on the catalyst du-ring UV irradiation was successfully monitored by use of IEC/CEC under optimized mobile-phase conditions (6 mM tartaric acid and 3 mM 18-crown-6). It was found that the products formed depended on whether or not a mole-cule contained a hydroxylated nitrogen moiety or other hydroxyl group.