A fast separation of alkali and alkaline earth metal cations and ammonium was carried out by capillary electrochromatography on monolithic octadecylsilica columns of 15 cm length and 100 μm inner diameter using water/methanol mixtures containing acetic acid as mobile phase. On-column contactless conductivity detection was used for quantification of these non-UV-absorbing species. The method was also extended successfully to the determination of small amines as well as of amino acids, and the separation selectivity was optimized by varying the composition of the mobile phase. Detection limits of about 1 μM were possible for the inorganic cations as well as for the small amines, while the amino acids could be quantified down to about 10 μM. The separation of 12 amino acids was achieved in the relatively short time of 10 min. © 2009 Elsevier B.V. All rights reserved.

Mai T.D., Pham H.V., Hauser P.C.

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Từ khóa : Alkaline Earth metal cations; Capacitively coupled contactless conductivity detection; Capillary electrochromatography; Contactless conductivity detection; Detection limits; Fast separation; Inner diameters; Inorganic cations; Mobile phase; Octadecylsilica; Organic cations; Separation selectivity; Water/methanol mixture; Alkaline earth metals; Amination; Amino acids; Ammonium compounds; Chromatography; Light metals; Organic acids; Positive ions; Separation; Amines; acetic acid; alkali metal; alkaline earth metal; amino acid derivative; ammonia; cation; metal ion; methanol; silicon dioxide; water; amino acid analysis; article; capillary electrochromatography; chemical composition; column chromatography; conductance; controlled study; phase separation; priority journal; process optimization; quantitative analysis; separation technique; Acetic Acid; Amines; Amino Acids; Capillary Electrochromatography; Cations; Electric Conductivity; Electrochemistry; Lithium; Metals, Alkali; Metals, Alkaline Earth; Methanol; Quaternary Ammonium Compounds; Silicon Dioxide; Surface Properties; Water