Thermo Scientific Dionex IonPac CS17 Cation-Exchange Column

Significance of the Topic

Ion exchange chromatography remains an indispensable tool in analytical chemistry for the separation and quantitation of cations and amines in complex matrices. The ability to resolve inorganic cations alongside hydrophobic and polyvalent amines without organic modifiers addresses critical needs in environmental monitoring, food safety, power plant water treatment and industrial process control.

Objectives and Overview

This article presents the Thermo Scientific Dionex IonPac CS17 cation exchange column as a universal solution for separating Group I and II cations and a broad range of amines, including biogenic amines, alkylamines, diamines and alkanolamines. It evaluates column performance in multiple formats and explores gradient elution strategies that avoid organic solvents, simplify workflow and maintain baseline stability.

Methodology and Instrumentation

The CS17 resin features a grafted carboxylate exchanger on a macroporous ethylvinylbenzene/divinylbenzene substrate. Columns are available in analytical bore (4×250 mm and 2×250 mm), microbore and capillary (0.4×250 mm) formats. Eluents are aqueous methanesulfonic acid gradients generated reagent free by an EG module. Suppression is achieved using self regenerating cation suppressors (CSRS 300) or capillary electrolytic suppressors (CCES 300). Typical conditions include elevated temperatures (30 to 40 °C), flow rates from 1.6 mL/min to 10 μL/min and injection volumes from 25 μL down to 400 nL.

Main Results and Discussion

Gradient and step-change elution demonstrated enhanced resolution of adjacent monovalent cations and dimethylamine with minimal baseline shift. The capillary format achieved high mass sensitivity with reproducible retention times. Biogenic amines such as putrescine, cadaverine, spermidine and histamine were separated from common cations under acidic gradient conditions, with suppressed conductivity or amperometric detection offering selective quantitation. Power plant amine additives, including hydrazine, ethanolamine, morpholine and cyclohexylamine, were resolved at ppb levels. Alkanolamines (mono-, di- and triethanolamine) and low-molecular-weight alkylamines displayed sharp, symmetric peaks without organic solvent. Diamines eluted cleanly after the six common cations using a simple acidic gradient despite large gradient swings.

Benefits and Practical Applications

• Universal separation of inorganic cations and a wide range of amines without organic modifiers
• Excellent peak shapes and high efficiency due to grafted hydrophilic exchanger
• Reagent free eluent generation reduces chemical handling and baseline drift
• Multiple column formats support high-throughput and trace analysis with low eluent consumption
• Compatibility with suppressed conductivity and amperometric detection enhances specificity

Future Trends and Applications

Advances in resin grafting and suppressor technology will continue to expand selectivity and robustness. Integration with mass spectrometry and microfluidic platforms could enable ultratrace analysis of amines in biological and environmental samples. Continued miniaturization and automation will support real-time monitoring in industrial processes and decentralized testing laboratories.

Conclusion

The Dionex IonPac CS17 column offers a versatile, solvent-free approach for simultaneous analysis of inorganic cations and a broad spectrum of amines. Its high efficiency, minimal baseline shift and multiple format options make it a valuable tool for routine and trace analysis across environmental, food, power plant and industrial applications.

Used Instrumentation

• Dionex IonPac CS17 analytical columns (4×250 mm, 2×250 mm), microbore and capillary (0.4×250 mm)
• Dionex CG17 guard columns and capillary guard
• Thermo Scientific Dionex Eluent Generator for methanesulfonic acid gradients
• Suppression modules: CSRS 300 and CCES 300
• Cation trap columns: Dionex CTC and CR-CTC II