Thermo Scientific Dionex IonPac IC column selection guide

Significance of the Topic

Ion chromatography is a cornerstone analytical technique in environmental, industrial, pharmaceutical and food laboratories for the separation and quantitation of charged species. Selecting the optimal IonPac column directly influences sensitivity, resolution and analysis speed, enabling reliable trace‐level determinations and high‐throughput workflows.

Objectives and Overview

The Thermo Scientific™ Dionex™ IonPac™ column selection guide compiles a comprehensive listing of anion hydroxide, anion carbonate, cation exchange, ion‐exclusion and specialty columns. Each entry details part numbers, column format, capacity, recommended applications and target analytes to streamline method development and column choice.

Methodology and Instrumentation

Separation is achieved using suppressed conductivity detection. Key methodological elements include:

• Eluent systems based on hydroxide or carbonate for anion analysis and diluted acids for cations
• Isocratic and gradient modes for targeted resolution of polarizable and polyvalent ions
• Capillary and standard bore formats to balance sensitivity, speed and solvent consumption

Instrumentation Used

The guide assumes use of:

• Thermo Scientific Dionex High‐Pressure Ion Chromatography (HPIC) systems
• Suppressed conductivity modules
• Dionex IonPac Eluent Concentrates for reproducible mobile phase preparation

Main Results and Discussion

Columns are grouped by application focus and capacity:

• Anion Hydroxide Columns (AS32‐Fast, AS31, AS30, AS28‐Fast, AS27, AS26, AS25, AS24A, AS24, AS21, AS20, AS19‐4µm, AS19, AS18‐Fast‐4µm, AS18‐Fast, AS18, AS17‐C, AS16‐4µm, AS16, AS15, AS11‐HC‐4µm, AS11‐HC, AS11, Fast Anion IIIA) – tailored for haloacetic acids, oxyhalides, inorganic anions, organic acids and trace anion profiling in drinking water, industrial and complex matrices
• Anion Carbonate Columns (AS29‐Fast‐4µm, AS23‐4µm, AS23, AS22‐Fast‐4µm, AS22‐Fast, AS22, AS14A, AS14, AS12A, AS9‐HC, AS4A‐SC) – optimized for high ionic strength samples, rapid separations and compliance with EPA and ISO methods
• Cation Exchange Columns (CS20, CS19‐4µm, CS19, CS18, CS17, CS16‐Fast‐4µm, CS16‐4µm, CS16, CS12A, CS12A‐5µm, SCS 1) – for amines, alkali and alkaline earth cations, alkanolamines, trace metals and wide concentration ranges
• Ion‐Exclusion and Specialty Columns (ICE‐AS1, ICE‐AS6, ICE‐Borate, AmG‐3µm C18, AS7, CS5A) – for organic acids, alcohols, borate monitoring, chromium speciation, transition metals and antibiotic impurity profiling

Benefits and Practical Applications

Key advantages include:

• Fast, sub‐5-minute separations with high‐pressure formats
• Wide dynamic range from high µeq capacities to low µeq capillaries for trace ppt determinations
• Enhanced peak efficiency and resolution for complex and co‐eluting species
• Compliance with regulatory methods (EPA, USP, ISO, ASTM) for water quality and pharmaceutical testing
• Scalable formats to minimize solvent use and operating costs

Future Trends and Applications

Emerging developments will focus on:

• Two-dimensional IC workflows to tackle highly complex mixtures
• Further miniaturization with capillary and micro-bore columns for ultra-low flow analysis
• Advanced stationary phase chemistries to extend selectivity for new anionic and cationic targets
• Seamless hyphenation with mass spectrometry for structural confirmation
• Green IC strategies to reduce reagent consumption and environmental impact

Conclusion

The Dionex IonPac column selection guide empowers analysts to match column chemistries, capacities and formats to specific application requirements, achieving robust, high‐throughput ion chromatographic performance across environmental, industrial and pharmaceutical sectors.