High-capacity cation-exchange column for enhanced resolution of adjacent peaks of cations in ion chromatography.
One of the advantages of ion chromatography [Anal Chem. 47 (1975) 1801] as compared to other analytical techniques is that several ions may be analyzed simultaneously. One of the most important contributions of cation-exchange chromatography is its sensitivity to ammonium ion, which is difficult to analyze by other techniques [J. Weiss, in: E.L. Johnson (Ed.), Handbook of Ion Chromatography, Dionex, Sunnyvale, CA, USA]. The determination of low concentrations of ammonium ion in the presence of high concentrations of sodium poses a challenge in cation-exchange chromatography [J. Weiss, Ion Chromatography, VCH, 2nd Edition, Weinheim, 1995], as both cations have similar selectivities for the common stationary phases containing either sulfonate or carboxylate functional groups. The task was to develop a new cation-exchange stationary phase (for diverse concentration ratios of adjacent peaks) to overcome limitations experienced in previous trails. Various cation-exchange capacities and column body formats were investigated to optimize this application and others. The advantages and disadvantages of two carboxylic acid columns of different cation-exchange capacities and different column formats will be discussed.
Rey
M A
MA
Dionex Corporation, Sunnyvale, CA 94085, USA. maria.rey@dionex.com
D000588:Amines / Q000302:isolation & purification; D002411:Cation Exchange Resins; D002412:Cations / Q000302:isolation & purification; D002852:Chromatography, Ion Exchange / Q000295:instrumentation*; D006863:Hydrogen-Ion Concentration; D013696:Temperature
D000588:Amines; D002411:Cation Exchange Resins; D002412:Cations