Comparison of Acclaim Surfactant Plus vs C18 for Simultaneous Separation of Cationic, Nonionic, Amphoteric and Anionic Surfactants

Significance of the Topic

The simultaneous analysis of diverse surfactant classes—cationic, nonionic, amphoteric and anionic—is critical for quality control in personal care, environmental monitoring and industrial formulations. Traditional reversed-phase columns (e.g., C18) often fail to resolve surfactants with similar hydrophobicity, leading to coelution and inaccurate quantification.

Objectives and Study Overview

This study compares Thermo Scientific™ Acclaim™ Surfactant Plus, a mixed-mode column combining reversed-phase and anion-exchange mechanisms, with a conventional C18 column. The goal is to assess their selectivity, resolution and robustness for simultaneous separation of eight representative surfactants.

Methodology and Instrumentation

A Thermo Scientific™ Dionex™ UltiMate™ 3000 RSLC system was used for chromatographic separations at 30 °C and 0.6 mL/min flow rate. The gradient elution employed mobile phase A (acetonitrile) and B (100 mM ammonium acetate, pH 5.2) over 15 minutes. Injection volume was 5 μL. Detection was performed using a Thermo Scientific™ Dionex™ Corona™ ultra Charged Aerosol Detector (gain 100 pA, filter medium, nebulizer at 20 °C). Eight surfactants were tested at 100–400 μg/mL: xylene sulfonate, laurylpyridinium, lauryldimethylbenzylammonium, Triton X-100, cetyl betaine, decyl sulfate, dodecyl sulfate and linear alkylbenzene sulfonate.

Main Results and Discussion

The Acclaim Surfactant Plus column achieved baseline separation of all eight surfactants in the order of cationic → nonionic → amphoteric → anionic. Peak shapes were sharp and symmetrical, demonstrating effective interaction with both hydrophobic and ionic moieties. Under identical conditions, the C18 column exhibited coelution of amphoteric and anionic analytes due to lack of ionic retention, resulting in incomplete resolution.

Benefits and Practical Applications

• Enhanced selectivity: Mixed-mode retention enables clear class-based elution without method modification.
• Improved quantification: Baseline separation reduces interference and enhances detector response accuracy.
• Workflow efficiency: A single run addresses multiple analyte classes, lowering analysis time and solvent consumption.
• Versatility: Applicable to QC of detergents, pharmaceutical formulations and environmental samples containing complex surfactant mixtures.

Future Trends and Potential Uses

Advances in mixed-mode column chemistries are expected to deliver even broader analyte compatibility, including zwitterionic and polymeric surfactants. Integration with high-resolution mass spectrometry and automated sample preparation will further streamline multi-class surfactant profiling in regulatory and research laboratories.

Conclusion

The Thermo Scientific™ Acclaim™ Surfactant Plus column demonstrates superior resolving power for simultaneous analysis of cationic, nonionic, amphoteric and anionic surfactants compared with a C18 stationary phase. Its mixed-mode design supports robust, high-throughput workflows and reliable quantification across diverse applications.

Instrumentation Used

• Column: Thermo Scientific™ Acclaim™ Surfactant Plus, 3 µm, 3.0 × 150 mm
• LC System: Thermo Scientific™ Dionex™ UltiMate™ 3000 RSLC
• Detector: Thermo Scientific™ Dionex™ Corona™ ultra Charged Aerosol Detector
• Mobile Phases: Acetonitrile; 100 mM Ammonium acetate (pH 5.2)