Fast Gas Chromatography - Increase GC Speed Without Sacrificing Resolution

Significance of the topic

Fast gas chromatography (Fast GC) enables laboratories to accelerate sample throughput by reducing analysis times without compromising the resolution needed to separate and identify target compounds. This approach delivers cost savings, higher sample capacity and maintains analytical quality across diverse sectors such as environmental testing, petrochemicals, food, flavor and fragrance, and clinical analysis.

Objectives and study overview

This application note outlines the Six Principles of Fast GC and demonstrates their combined effect through comparative chromatograms. The goal is to guide analysts in systematically applying these principles to any GC method to achieve analysis times up to tenfold faster while retaining or improving peak separation.

Methodology and instrumentation

Analyses were conducted on conventional and Fast GC configurations using capillary columns from Merck’s Supelco portfolio. Typical setups included:

• Columns: SLB®-5ms (30 m×0.25 mm×0.25 µm, 20 m×0.18 mm×0.18 µm, 15 m×0.10 mm×0.10 µm), Equity®-1 (15 m×0.10 mm×0.10 µm), Omegawax® (15 m×0.10 mm×0.10 µm), SUPELCOWAX® 10 (10 m×0.10 mm×0.10 µm)
• Carrier gases: helium or hydrogen at optimized linear velocities (25–120 cm/s)
• Oven programs: elevated temperature ramp rates (20–80 °C/min) and reduced isothermal hold times
• Injection: split or splitless modes with high split ratios (up to 800:1) for narrow-ID columns
• Detectors: FID, ECD or MSD with scan ranges m/z 40–450 as applicable

Main results and discussion

By sequentially applying:

• Principles 1–3 (shorter column length, higher temperature/ramp rate, increased carrier velocity) to reduce retention time
• Principles 4–6 (narrower ID, hydrogen carrier gas, thinner film thickness) to recuperate or enhance resolution

Complete GC runs of semivolatiles and PAHs were shortened from ~20 min to ~8.5 min with equal or improved peak separation. Tutorial figures illustrate intermediate steps, highlighting the importance of operating at the optimal linear velocity for each column and gas combination to minimize plate height (H) and maximize efficiency.

Benefits and practical applications

Fast GC offers:

• Up to three- to ten-fold faster analysis times
• Lower operational costs through reduced instrument and staffing requirements
• Higher profitability by accommodating more samples per shift
• Seamless integration into existing methods with no loss of analytical quality

Applications span US EPA volatiles and semivolatiles, pesticide and PCB testing, fuel and oil profiling, fatty acid methyl ester analysis in food and clinical matrices, essential oil fingerprinting, and aroma compound screening in fragrances.

Future trends and possibilities

Emerging developments include:

• Advanced ionic-liquid stationary phases tailored for target compound classes
• Miniaturized injector liners and reduced-volume ovens to push ramp rate limits higher
• Automated method translation tools to convert legacy GC methods to optimized Fast GC protocols
• Integration with high-throughput sample preparation and multi-dimensional GC platforms

Such innovations will further expand Fast GC utility across regulatory, industrial, and research laboratories.

Conclusion

Fast GC, grounded in the Six Principles, delivers significant time savings and resolution gains. By optimizing column dimensions, carrier gas choice, linear velocity, temperature programming, and stationary phase properties, analysts can enhance throughput without sacrificing analytical performance. This approach is applicable across a broad spectrum of GC applications and supports evolving laboratory demands for efficiency and data quality.

References

• Merck KGaA. Fast Gas Chromatography: Increase GC Speed Without Sacrificing Resolution, Merck Application Note MK_BR4748EN (2020).
• US EPA Methods 624, 8260, 8270, 8081, 8082 for volatile, semivolatile, pesticide, and PCB analysis.