Acclaim Mixed-Mode HPLC columns

Significance of the topic

Mixed-mode liquid chromatography integrates two or more interaction mechanisms on a single stationary phase, enabling the separation of analytes with diverse chemical properties. By combining reversed-phase, ion-exchange and/or HILIC functionalities, these columns overcome limitations of single-mode columns and deliver enhanced resolution for complex samples in pharmaceutical, environmental, food, and biochemical analyses.

Study Objectives and Overview

This work reviews Thermo Scientific Acclaim mixed-mode HPLC columns—including WAX-1 (weak anion-exchange/RP), WCX-1 (weak cation-exchange/RP), HILIC-1 (HILIC/RP), and tri-modal Trinity P1 and P2 phases. Key aims are to illustrate adjustable selectivity, demonstrate resolution improvements for challenging mixtures, and highlight practical applications across multiple sample types.

Methodology and Instrumentation

Acclaim mixed-mode columns are silica-based supports bonded with combinations of hydrophobic chains, charged groups and diol/HILIC termini. Selectivity tuning is achieved by varying mobile phase pH, ionic strength, and organic solvent content. Representative separations include mono-carboxylic acids, pharmaceutical active ingredients with counterions, soft-drink additives, surfactants and polyethylene glycols, engine-coolant degradation products, catecholamines, ethanolamines and beverage electrolytes.

Instrumentation Used

• Conventional HPLC/UHPLC systems with UV detection (210–225 nm).
• Charged aerosol detector for non-UV-active compounds.
• LC-MS/MS QTRAP with electrospray ionization for trace amine analysis.

Main Results and Discussion

The mixed-mode columns consistently resolved neutral, acidic and basic analytes under isocratic and gradient conditions without ion-pairing agents:

• WAX-1: Effective separation of organic acids, pain-relief drugs and soft-drink sweeteners by switching anion-exchange and RP retention through pH, buffer concentration and organic content adjustments.
• WCX-1: Simultaneous BNA (basic, neutral, acidic) separations and high-resolution catecholamine analysis via combined cation-exchange and RP interactions.
• HILIC-1: Dual-mode surfactant profiling (total vs ethoxylate distribution) and high-performance PEG fractionation using HILIC/RP balance.
• Trinity P1/P2: Tri-modal phases delivering concurrent separation of pharmaceuticals with mono-/multivalent counterions, ethanolamines by MS detection, sports drink electrolytes and common buffering agents in a single run.

These results underscore the robustness and versatility of mixed-mode chemistries for complex sample matrices.

Benefits and Practical Applications

• Flexible method development on one column for analytes of widely varying polarity and charge.
• Avoidance of ion-pair reagents enhances MS compatibility and simplifies mobile phases.
• Improved resolution of challenging mixtures in pharmaceutical QA/QC, environmental monitoring, food and beverage testing, and metabolomics.
• Compatibility with UHPLC and advanced detectors broadens analytical scope.

Future Trends and Applications

Ongoing developments are expected to include expanded pH-stable mixed-mode chemistries, greener solvent systems, integration with high-throughput UHPLC-MS workflows, and tailored phases for omics, biomolecule characterization and field-deployable environmental assays.

Conclusion

Thermo Scientific Acclaim mixed-mode columns offer a powerful, adaptable solution for high-resolution separation of complex mixtures, achieving adjustable selectivity through fine control of mobile phase conditions. Their broad applicability, from routine pharmaceutical assays to advanced MS-based trace analysis, positions them as essential tools for modern analytical laboratories.

Reference

• Zhang K, Liu X. Mixed-Mode chromatography in pharmaceutical and biopharmaceutical applications. J Pharm Biomed Anal. 2016;128:73–88.
• Liu X, Pohl C. Exploring Mixed-Mode Chromatography: Column Chemistry, Properties, and Applications. Thermo Fisher Scientific PN21137.
• Thermo Fisher Scientific. PN-PITTCON Mixed-Mode Chromatography Application Note.
• K. Zhang, X. Liu. J Pharm Biomed Anal. 2016;128:73–88.