Column Selections and Their Effects on Compact Capillary Liquid Chromatography Systems

A new study, published in the Journal of Chromatography A, compared the performances of various columns available on the market that can be used with compact and portable capillary LC systems.

The study, done by researchers from Rowan University, used a compact capillary LC system with a UV-absorbance detector (1). Six columns within the 0.2–0.3 mm internal diameter (i.d.) range, which varied in length, pressure limits, and packed stationary phases of different particle diameters and morphologies, were studied by separating a mixture of standard alkylphenones. By determining the number of theoretical plates, comparing kinetic plots, and calculating both kinetic performance and Knox-Saleem limits, these scientists hoped to identify the ideal operating conditions for capillary LC systems.

James P. Grinias, associate professor at Rowan University and corresponding author of this study, told LCGC that this research could create new opportunities for environmental testing directly in the field, clinical analysis directly in healthcare settings, process monitoring in manufacturing plants, and more. Moreover, these systems are comparable to their analytical-scale counterparts.

“The results we found were rather comparable to previous studies focused on analytical-scale columns by other groups,” he said. “One conclusion is that achieving higher pressure limits on commercially available capillary-scale LC columns will be very useful in improving throughput during method development, as has previously been observed with the transition from HPLC to UHPLC.”

According to Grinias, the research done here is applicable to instruments and columns of many sizes and formats.

“Though it may require financial investment in proper instrumentation, the overall methodology using miniaturized systems significantly reduces consumable costs,” he said. “Perhaps more importantly, the methods are far greener, which many companies are now prioritizing.”

Grinias and his team plans to use this platform in biopharmaceutical analysis, specifically by focusing on monoclonal antibody analysis workflows. The group’s initial projects with the instrument partly focused on analyzing drugs of abuse, such as cocaine and methamphetamine. They are soon returning to this topic to improve detection limits for this analyte class, using recent instrument developments as a reference.

Capillary LC is a versatile technology that can have applications in multiple scientific fields, and studies like these have the potential to enhance how these systems are utilized.

“I am hoping that the growing area of research around compact/portable capillary-scale systems shows that this type of instrument may be more readily adapted into a much wider range of LC-based analytical workflows,” Grinias said.

Reference

(1) Foster, S. W.; Gates, E. P.; Peaden, P. A.; Calugaru, S. V.; West, W. R.; Lee, M. L.; Grinias, J. P. Column selection considerations in compact capillary liquid chromatography. J. Chromatogr. A 2023, 464067. DOI: https://doi.org/10.1016/j.chroma.2023.464067