Optimizing GC Parameters for Faster Separations with Conventional Instrumentation

Significance of the Topic

Objectives and Overview of the Study

• Evaluate transfer of conventional GC methods to Thermo Scientific TraceGOLD Fast GC columns.
• Assess impact on analysis speed and chromatographic performance with minimal method changes.
• Aim for up to 50% faster separations without compromising resolution.

Methodology and Instrumentation

• Systematic variation of column length, internal diameter, film thickness, carrier gas linear velocity, and temperature ramp rate.
• Model analyte sets include polyaromatic hydrocarbons, phenols, and fatty acid methyl ester mixtures.
• Comparative tests conducted under constant helium flow with split injections and FID detection.

Used Instrumentation

• Gas chromatograph equipped with a split/splitless injector and flame ionization detector.
• Thermo Scientific TraceGOLD TG-5SilMS and TG-5MS columns in dimensions 30 m×0.25 mm×0.25 µm, 20 m×0.15 mm×0.15 µm and variants.
• Helium carrier gas at controlled flow rates between 0.6 and 3.0 mL/min.

Main Results and Discussion

• Halving column length (30→15 m) reduced PAH run time by 34% with acceptable resolution loss in critical pairs.
• Narrowing the bore (0.25→0.15 mm) enhanced efficiency and optimal linear velocity (from 28.5 to 32.7 cm/s), offsetting shorter column effects.
• Reducing film thickness (0.50→0.25 µm) in phenol separations increased resolution and cut analysis time by 13%.
• Higher temperature ramps and increased carrier velocity synergistically decreased run times up to 50% while keeping baseline separation.
• FAME mixture (C8–C24) method transferred to fast column (20 m×0.15 mm×0.15 µm) achieved a 30–50% reduction in total run time without resolution compromise.

Benefits and Practical Applications

• Enhanced sample throughput and reduced per-sample operational costs.
• Minimal method redevelopment required for laboratories using conventional GC setups.
• Consistent or improved peak resolution across various chemical classes.

Future Trends and Possibilities

• Broader adoption of fast GC columns in QA/QC, research, and industrial analytics to meet rising throughput demands.
• Integration with advanced carrier gases such as hydrogen and rapid MS detection for high-speed, high-sensitivity analysis.
• Development of automated method translation tools to streamline fast GC implementation.

Conclusion

• Transferring methods to fast GC columns cuts analysis time by up to 50% with preserved resolution.
• Careful optimization of key parameters ensures performance parity without hardware changes.
• Fast GC columns offer a practical and cost-effective path to boosting laboratory productivity.

References

1. Grob RL, Barry EF. Modern Practice of Gas Chromatography. Wiley, Hoboken, 2004.