New Developments in Chromatography at Supelco

Significance of the Topic

Innovations in gas chromatography (GC) stationary phases and sampling devices are critical for advancing the separation, identification, and quantification of complex mixtures in fields such as environmental analysis, food and beverage quality control, petrochemical testing, and biomedical research. The development of ionic liquid (IL)–based columns and enhanced solid-phase microextraction (SPME) fibers addresses ongoing challenges in isomeric separation, alcohol and water coelution, trace volatile contaminants, and harsh matrix environments.

Objectives and Overview of the Study

This summary reviews new product developments presented by Supelco at ISCC Fort Worth (May 19, 2015). The work led by L. M. Sidisky introduces a suite of GC capillary columns—SLB-35ms, SLB-IL111, SLB-IL60, SLB-IL D3606, SLB-IL PAH—and IL94/107/200 phases for water–solvent analysis, along with over-coated PDMS/DVB SPME fibers. The goal was to demonstrate improved selectivity, extended thermal limits, enhanced resolution of positional and geometric isomers, and greater durability in complex sample matrices.

Methodology and Instrumentation Used

Analytical methods combined temperature-programmed and isothermal GC separations with different stationary phases. Key instruments and conditions included:

• GC systems fitted with FID (250 °C), MSD (full scan 45–500 m/z) or TCD detectors
• Carrier gases: hydrogen (1 mL/min) or helium (1.2 mL/min)
• Capillary columns: SLB-35ms (35% phenyl, 350 °C max), SLB-IL111, SLB-IL60, SLB-IL D3606, SLB-IL PAH, SLB-5ms, IL94, IL107, IL200
• Column dimensions ranging from 20 m to 200 m length, 0.18–0.25 mm i.d., film thickness 0.05–0.20 µm
• SPME fibers: IL-coated phases and PDMS/DVB over-coated variants for headspace and direct immersion sampling
• Sample types: partially hydrogenated vegetable oil FAMEs, fusel alcohols, reformulated gasoline oxygenates, PAH standards, organic solvents in water, distilled spirits and liqueurs

Main Results and Discussion

• SLB-35ms: A robust 35% phenyl column with a 350 °C limit offered general-purpose separations with good peak shape for semi-volatile analytes.
• SLB-IL111 vs SP-2560: IL111 exhibited increased retention of cis-FAME isomers and complementary selectivity for C18:1 and C18:2 cis/trans positional isomers under isothermal conditions.
• SLB-IL60 vs polyethylene glycol (PEG): Demonstrated superior resolution of C18:1 and C18:2 FAME geometric isomers and effective separation of 2- and 3-methylalkanols, reducing coelution encountered on Supelcowax 10.
• SLB-IL D3606: A specialized IL phase resolved benzene and toluene from ethanol, isobutanol and other alcohol interferences with resolution (Rs) values of 12.6 and 45 for critical pairs; also applied to multi-component gasoline oxygenates.
• PAH separations: SLB-IL PAH provided comparable or improved resolution of 16 EPA priority PAHs relative to conventional silphenylene phases, enabling faster analyses.
• Ionic liquid water–solvent separations: IL94, IL107 and IL200 phases achieved baseline separation of methanol, ethanol, acetone, isopropanol, n-propanol, 1,4-dioxane, butanol and water using TCD detection.
• SPME IL107 fiber: Effectively extracted volatile solvents and trace compounds from aqueous standards and spirit beverages (Grappa, Vodka, Ouzo), identifying key alcohols, furfural, phthalates and aromatic derivatives.
• Over-coated PDMS/DVB fibers: A thin external PDMS layer extended fiber lifetime in sugar-rich matrices, minimized fouling, reduced background signals and maintained analyte uptake efficiency.

Benefits and Practical Applications

• Enhanced selectivity for positional/geometric isomers improves quantitation accuracy.
• High thermal stability expands the range of volatile and semi-volatile targets.
• Robust IL phases resist sample matrix interferences in alcohol-rich and aqueous samples.
• Improved fiber longevity and reduced maintenance costs for routine SPME analyses.
• Applications in food and beverage authentication, environmental monitoring, petrochemical quality control and forensic testing.

Future Trends and Potential Applications

Further expansion of ionic liquid stationary phases may focus on tailored chemistries for chiral separations, enhanced coupling with two-dimensional GC and mass spectrometry, and automation using machine learning for method development. Continued innovation in SPME fiber coatings will support rapid in-field sampling and high-throughput laboratory workflows.

Conclusion

Supelco’s new chromatographic products demonstrate significant advances in selectivity, thermal robustness and matrix tolerance. Ionic liquid GC columns and over-coated SPME fibers offer powerful tools for challenging separations, enabling analysts to achieve higher resolution, lower detection limits and greater operational efficiency across diverse application areas.

References

• Souza-Silva E. A., Pawliszyn J. Overcoated PDMS/DVB SPME Fibers: Fabrication and Performance. Anal. Chem. 84(15), 6933–6938 (2012).