Cation Exchange

Hamilton Cation Exchange Columns

Hamilton’s cation exchange columns are engineered for high-performance separations of positively charged analytes using strong, predictable ion-exchange interactions. In cation exchange chromatography, the stationary phase carries a negatively charged surface that selectively retains cations. The greater the positive charge of the analyte, the stronger its interaction with the stationary phase—resulting in increased retention, enhanced resolution, and improved selectivity for ionic and ionizable compounds.

Elution is precisely controlled by the aqueous mobile phase, where adjustments in pH and ionic strength fine-tune analyte interaction with the resin. Increasing ionic strength or shifting pH disrupts electrostatic attractions, enabling analytes to elute in a predictable order. These flexible elution strategies make cation exchange chromatography highly effective across environmental, pharmaceutical, food and beverage, and research applications.

Because Hamilton uses robust polymeric stationary phases instead of silica, these columns tolerate aggressive mobile phases—including very high pH conditions (>11)—and withstand elevated temperatures far beyond the limits of silica-based materials. This durability allows rigorous cleaning, longer column lifetimes, and reliable performance under demanding analytical conditions.

Key Definitions ▸
Cation Exchange Chromatography
A chromatographic method using a negatively charged stationary phase to retain positively charged analytes. Stronger cationic charge results in stronger interactions and longer retention times.
Ionic Strength
A measure of the total ion concentration in the mobile phase. Higher ionic strength reduces electrostatic attraction between analytes and the stationary phase, promoting earlier elution.
pH Control
Adjusting the mobile phase pH affects analyte charge state and binding strength. Higher pH can weaken cation retention, enabling selective elution and improved resolution.
Polymeric Stationary Phase
A chemically durable support material resistant to extreme pH and elevated temperatures. Polymeric phases outperform silica under harsh IC conditions and offer extended column lifetimes.
High-pH Compatibility
The ability of a column to withstand mobile phases with pH values above 11. Polymeric supports excel in high-pH applications where silica columns degrade rapidly.
Frequently Asked Questions ▸

What makes Hamilton cation exchange columns suitable for positively charged analytes?

These columns feature a negatively charged polymeric stationary phase that strongly retains positively charged molecules through electrostatic attraction. Greater positive charge results in higher retention, enabling precise and predictable separations.

How are compounds eluted in cation exchange chromatography?

Elution is controlled using aqueous buffers where pH and ionic strength determine analyte retention. Increasing ionic strength or adjusting pH weakens the electrostatic interactions, allowing compounds to elute in a predictable sequence.

Why are polymeric stationary phases beneficial for high-pH and high-temperature applications?

Polymeric materials are chemically resistant and maintain structural integrity under extreme pH conditions (>11) and elevated temperatures—conditions that quickly degrade silica-based columns. This results in longer lifetimes and greater method flexibility.