Alternative approach to enhancing cation selectivity in ion chromatography

• Published in: Journal of Chromatography A Vol. 1039; no. 1; pp. 123 - 127
• Main Authors: Saari-Nordhaus, Raaidah, Anderson, James M
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 11.06.2004; Elsevier
• Subjects: Analysis; Analytical biochemistry: general aspects, technics, instrumentation; Analytical chemistry; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Cations - analysis; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography, Liquid - methods; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General pharmacology; Inorganic cations; Medical sciences; Pharmacology. Drug treatments; Selectivity; Sensitivity and Specificity; Inorganic cations; Selectivity; Inorganic cation; Ion chromatography
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2004.02.004

A new approach to enhance cation selectivity in ion chromatography (IC) is described. Two packings, one carrying a conventional carboxylate cation exchanger and the other carrying a crown ether (CE) phase are packed into two separate columns and used in series. The resolution between sodium and ammonium and between ammonium and potassium is increased significantly. The two stationary phases may also be mixed and packed into a single column. The selectivity of the cations can be adjusted easily by varying the dimensions of the carboxylate and CE columns (in the two-column configuration), or by changing the ratio of the carboxylate cation exchanger to the CE packing (in the single-column configuration). These new systems separate ammonium and sodium, even when the sodium concentration is 5000 times higher. Amines such as ethanolamine and triethanolamine can also be separated from the alkali and alkaline-earth cations.