Primesep® 100

Importance of the topic

Mixed-mode chromatography combines multiple separation interactions in a single stationary phase, offering versatile retention mechanisms that overcome limitations of single-mode LC. Primesep 100 columns integrate hydrophobic and ionizable functionalities, enabling efficient separation of diverse analytes ranging from neutral to charged species. This approach simplifies mobile phase composition, eliminates ion-pair reagents, and enhances method robustness for complex matrices in pharmaceutical, environmental, and industrial analyses.

Study objectives and overview

The article presents design principles and performance evaluation of SIELC’s Primesep 100 HPLC columns. Objectives include demonstrating mixed-mode separation capabilities, mobile phase tuning strategies, and the column’s stability across wide pH and solvent conditions. The work illustrates applications for organic and inorganic ions, polar and nonpolar compounds, and preparative-scale separations.

Methodology and instrumentation

Mixed-mode separations were conducted using analytical and preparative HPLC systems equipped with UV, ELSD, RI, and mass spectrometry detectors. Primesep 100 columns (various dimensions and particle formats including fully porous and core-shell) were tested with mobile phases of acetonitrile, water, and volatile buffers (formate, acetate, phosphate, TFA). Gradient and isocratic methods explored influence of organic content, buffer concentration, pH, and gradient type on retention and selectivity.

Used instrumentation

• Analytical HPLC systems (5000–9000 psi capability)
• UV detectors (200–270 nm range)
• Evaporative Light Scattering Detector (ELSD)
• Refractive index detector (RI)
• Mass spectrometers (MS-compatible mobile phases)

Main results and discussion

The embedded C12 ligand with an acidic group (pKa ~1) provided hydrophobic, ion-exchange, and polar interactions without external ion-pair reagents. Mobile phase adjustments allowed control of interaction modes: high organic content favored reversed-phase, high buffer strength favored ion-exchange. Core-shell columns achieved high efficiency at elevated flow rates. Examples included separations of amino acids, nucleobases, ions, NSAIDs, herbicides, antibiotics, and complex mixtures. Gradient strategies reversed elution orders and improved resolution of compounds with diverse hydrophobicity and pKa characteristics.

Benefits and practical applications

• Single column enables reverse-phase, normal-phase, ion-exchange, and ion-exclusion modes.
• Tunable retention for neutral and ionizable analytes via mobile phase composition.
• No need for ion-pair reagents; compatible with MS, ELSD, UV, and RI detection.
• Resistant to dewetting in 100% aqueous media; stable pH range 1.0–7.0.
• Core-shell format offers UHPLC-like speed and efficiency on conventional HPLC systems.
• Simple scale-up from analytical to preparative separations without method changes.

Future trends and opportunities

Advances in mixed-mode stationary phases will expand applications in high-throughput screening, biopharmaceutical characterization, and complex environmental analyses. Integration with automated method development tools and AI-driven optimization can further enhance selectivity and robustness. Development of tailored ligands may address emerging challenges in chiral separations and glycomics.

Conclusion

Primesep 100 mixed-mode columns deliver versatile, reproducible separations across a wide range of analytes and modes. Their robust performance, simple mobile phase requirements, and adaptability to various detection systems make them a valuable tool in modern analytical laboratories. Future developments will likely extend mixed-mode chromatography’s impact in complex sample analysis.

Reference

No external references provided in source text.