Gas chromatography (GC) remains a cornerstone of analytical chemistry, but developing and optimizing methods can be complex. Diane Turner, Director and Senior Consultant at Anthias Consulting, recently provided expert guidance on GC method development in a Separation Science webinar titled “Expert Answers: GC Method Development”.
Turner stresses that method development is rarely linear. “The process is iterative. You try, evaluate, and adjust. That’s how you build methods that are not only effective but reproducible,” she expands. “It’s about building confidence in every step so that when something doesn’t look right, you know exactly which lever to adjust.”
Challenges and Troubleshooting
Throughout the session, Turner zeroes in on recurring pain points that scientists face in day-to-day GC work. She frames these as common stumbling blocks that many labs encounter, including:
- Peak shape issues: Poor peak shape often stems from problems at the inlet, such as leaks, incorrect split ratios, or poorly maintained liners. Turner explains that peak tailing or fronting can be traced back to these mechanical issues, but may also result from an unsuitable column phase. “If you see tailing, don’t just blame the column—look at your inlet first,” she advises. Selecting the right stationary phase for the analyte type is critical to ensuring sharp, symmetrical peaks.
- Retention time shifts: Subtle changes in oven temperature programming, carrier gas flow rates, or column dimensions can create drift in retention times that complicate reproducibility. Turner emphasizes that even a few degrees difference in temperature ramping can result in significant retention time shifts. “Always check what the oven is actually doing compared to what you’ve programmed,” she says. She advises checking calibration, verifying setpoints against actual values, and considering adjustments to ramp speeds or hold times.
- Matrix effects: Complex sample matrices often suppress or enhance signals, masking analytes of interest. Turner notes that when dealing with environmental or food samples, matrix interferences can obscure peaks entirely. “Sometimes the chemistry of the matrix is your biggest enemy. You have to clean it up or change the column selectivity to see your analytes clearly,” she explains. She suggests exploring sample cleanup techniques, selecting columns with different polarities, or using derivatization strategies to improve analyte detectability.
Turner also describes a case where unresolved peaks make quantification nearly impossible. The fix, she notes, is as simple as adjusting the carrier gas flow rate and re-evaluating column dimensions. “A small change in one parameter can unlock the separation you’re struggling with,” she emphasizes.
Practical Strategies for GC Success
Turner provides a roadmap for systematic method development:
Start with fundamentals: Instead of immediately trying complex oven programs or pressure pulsing techniques, Turner advises starting with simple, steady conditions. She emphasizes the importance of selecting the appropriate column length, internal diameter, and stationary phase from the outset, as these factors significantly influence the efficiency and selectivity of the separation. “Get the basics right first. If the foundation is weak, no amount of clever programming will save the method,” she advises.
Build in reproducibility: Turner explains that developing methods in isolation can be misleading if the ultimate goal is inter-laboratory transfer. She highlights the importance of using robust conditions that can be replicated across different GC systems. “A good method isn’t just about working on your instrument—it has to work on someone else’s too,” she reminds the audience. This includes verifying flow rates using calibrated flow meters, utilizing columns from multiple batches, and testing methods across multiple instruments when possible.
Keep detailed records: Proper documentation is essential for streamlining troubleshooting. Turner notes that many labs waste time by repeating errors because earlier experiments weren’t fully recorded. “Write everything down—even what didn’t work. That’s what saves you time the next time you face the same issue,” she stresses. She recommends maintaining a systematic log of temperature programs, flow settings, and sample preparation steps to quickly identify which adjustments lead to improvements.
She also touches on the importance of understanding sample preparation. In one example, residues in the injection system lead to repeated carryover problems. Cleaning protocols and attention to solvent compatibility quickly resolve the issue. Turner points out that overlooking sample prep can undo hours of careful method optimization. “Sample preparation is half the method—you can’t ignore it and expect good chromatography,” she cautions.
Audience Q&A
The Q&A segment showcased the practical focus of the webinar. Participants inquired about handling high-boiling compounds, enhancing sensitivity for trace analytes, and preventing column overload. Turner described practical adjustments that scientists can implement immediately, such as adjusting injection volumes, testing different split ratios, or extending equilibration times, offering immediate, actionable steps.
She highlights, for example, that for high-boiling compounds, extended temperature programs with longer hold times can improve elution, while for trace-level detection, fine-tuning injection techniques and optimizing detector settings can make the difference between missing and identifying a compound. “When you face a tough analyte, don’t give up—adjust your program and think about what the molecule really needs to travel through the column,” she encourages.
The Takeaway
Turner’s central message is clear: successful GC method development is about balancing technical knowledge with a structured, step-by-step approach. By applying these strategies, labs can avoid common pitfalls, save time in troubleshooting, and strengthen data reliability.
As Turner concludes, “GC method development doesn’t have to be overwhelming—if you approach it systematically, you can get to robust, transferable methods faster.”
For more detailed examples and full expert answers, watch the on-demand webinar at Separation Science.
Meet the Expert
Diane Turner is the Director and Senior Consultant at Anthias Consulting in the UK. With a background in analytical chemistry from Warwick University and extensive experience across environmental, petrochemical, and food sectors, she has become a leading authority in chromatography and mass spectrometry. Turner has trained and consulted for laboratories worldwide and authored numerous publications and is widely recognized for her ability to bridge practical troubleshooting with deep technical expertise. Through Anthias Consulting, she continues to provide training, consultancy, and method development services, supporting scientists in optimizing their analytical workflows.