Increased Retention of Polar Analytes Using CORTECS T3 Columns

Significance of the topic

Reversed-phase liquid chromatography (RP-LC) often struggles to retain polar analytes due to weak interactions with hydrophobic C18 phases. Enhanced retention of these compounds is critical for accurate quantification and separation of natural products, metabolites and pharmaceutical polar species in complex matrices.

Objectives and overview of the study

This application note evaluates the performance of CORTECS T3 columns compared to traditional solid-core C18 phases for isocratic separation of catechin and its related polar metabolites under highly aqueous conditions. The goal is to demonstrate increased retention, peak shape and robustness when analyzing strongly polar analytes.

Methodology and instrumentation used

An isocratic mobile phase (95:5 water:acetonitrile with 0.1% formic acid) was delivered at 0.6 mL/min and 30 °C on an ACQUITY UPLC H-Class system with Column Manager. Detection was performed at 280 nm using Empower 3 CDS. Multiple solid-core columns (1.6–2.7 µm) including CORTECS T3, CORTECS C18, HALO C18, Accucore C18 and Kinetex C18 were compared. Sample mixtures contained phloroglucinol, protocatechuic acid, catechin and epicatechin in water.

Main results and discussion

CORTECS T3 exhibited the largest pore size (120 Å) and lowest C18 bonding density among tested phases, facilitating improved access of polar analytes to silanol sites and resistance to dewetting under low organic eluent. On 2.7 µm columns, CORTECS T3 increased retention times for epicatechin by 16% and phloroglucinol by 4% relative to the next best (HALO C18 and Kinetex C18 respectively). On sub-2 µm formats, retention gains reached 19% for late-eluting and 8% for early-eluting peaks versus Kinetex. Enhanced retention translated into better resolution and peak shapes for early eluters, confirming improved polar interactions and phase stability in highly aqueous mobile phases.

Benefits and practical applications

• Increased retention of strongly polar analytes improves separation and detection sensitivity.
• Robust operation under low or no organic solvent conditions avoids phase collapse and peak distortion.
• Available in multiple particle sizes (1.6–2.7 µm) to optimize throughput and efficiency.
• Suitable for QA/QC and research laboratories analyzing polar natural products, metabolites or drug compounds.

Future trends and possibilities for application

With growing interest in green and ultra-high-throughput chromatography, T3-type phases may be further developed for micro- and nano-LC formats, direct coupling to mass spectrometry for polar metabolomics, and tailored surface chemistries to expand retention of charged or highly hydrophilic species. Integration with automated sample prep and data analytics will enhance screening of complex biological and environmental samples.

Conclusion

CORTECS T3 columns combine increased pore size and reduced C18 bonding density to deliver markedly improved retention and chromatographic performance for polar analytes under RP-LC conditions. Their resistance to dewetting and versatile particle size options make them valuable tools for robust, high-efficiency analysis of polar compounds in research and quality control settings.

References

• Walter TH, Iraneta P, Capparella M. Mechanism of retention loss when C8 and C18 HPLC columns are used with highly aqueous mobile phases. J Chromatogr A. 2005;1075:177–183.
• Majors RE. The Top 10 HPLC and UHPLC Column Myths: Part 1. LCGC Europe. 2013;26:584–592.