PFAS, Mycotoxins, and the Future of Food Safety Testing

Holly Lee of SCIEX

In collaboration with Separation Science

In a recent episode of our "Concentrating on Chromatography" podcast, we had the pleasure of speaking with Holly Lee, Global Technical Marketing Specialist at SCIEX. With a rich background spanning academic research, government regulation, and now industry innovation, Holly offered a profound look into the complex world of food and environmental analysis.

The conversation explored some of the most pressing challenges facing analytical laboratories today, from the persistent problem of PFAS to the hidden threat of masked mycotoxins and the constant drive for greater laboratory efficiency. This post delves into the key takeaways from our discussion, highlighting Holly’s expert perspective on the techniques and technologies shaping the future of food safety.

The Analyst's Journey: A Multi-Faceted Perspective

Holly's career path provides a unique lens through which to view the analytical chemistry landscape. Her journey began at the University of Toronto, where she studied the environmental processes of PFAS under the guidance of Professor Scott Mabury. She humorously recalls being "hooked onto this whirlwind" of PFAS after being captivated by the storytelling prowess of her professor, who used chemical structures to narrate their journey through the environment—from transformation in the atmosphere to bioaccumulation in wildlife.

This academic foundation led her to the Ontario Ministry of the Environment, where she gained rigorous experience in method validation, QA/QC, and hands-on sample preparation for a wide range of contaminants, including pesticides and pharmaceuticals. This experience as an end-user proved invaluable when she transitioned to SCIEX.

"My experience as a customer from the other end really helped with bringing feedback and experience from the field to help drive product development during my R&D days," Holly explained. This ability to relate to the "pain" of her customers, whether in method development or troubleshooting, has been a cornerstone of her success in her current global marketing role.

Tackling the "Toughest" Analytes: Ultra-Short-Chain PFAS

One of the most significant challenges in environmental and food analysis today is the detection of ultra-short-chain PFAS like trifluoroacetic acid (TFA). Holly described these compounds as "probably some of the toughest ones that I've had to work with."

Their high polarity and small size cause them to elute very early on standard C18 columns, often co-eluting with matrix interferences like inorganic ions. This leads to poor peak shape and compromised data quality. Holly detailed two primary challenges:

Chromatographic Retention: Achieving good retention and peak shape is critical. Holly credits a strong partnership with Phenomenex for developing a robust method using their Luna Omega PS C18 column, which offered the flexibility to optimize retention and separation through careful gradient tweaking.
Background Contamination: TFA is ubiquitous. "They are everywhere," Holly stated, "in our consumables... like pipet tips, LC vials, their inner solvents, their inner our LC system." This requires diligent screening of all lab materials and, in some cases, pre-cleaning steps to reduce background levels before analysis. Interestingly, she notes that while new labs can purchase "PFAS-free" tested products, older, well-flushed LC systems can sometimes be cleaner than brand-new ones—a "double-edged sword."

The Unpredictable World of Matrix Interference

For food analysis, Holly emphasized that the "biggest hurdle is probably matrix interference." The challenge lies in its unpredictability. Even between two samples of the same food, like lettuce, the interference profile can be completely different.

This is where good chromatography becomes paramount. "I can't stress... the importance of good chromatography method development," Holly said. "This is so key to not only show that you have good retention for the target PFAS that you're looking at, but also to make sure that they are very well separated from any matrix interference that could be present."

Key strategies include:

Column and Mobile Phase Selection: Experimenting with mobile phases is crucial. For instance, while methanol can offer a better signal for PFAS, acetonitrile might provide better separation from specific interferences, such as bile acids in seafood and eggs.
Sample Cleanup: Using Solid Phase Extraction (SPE) with the right sorbent can remove interferences before the sample is even injected.
Instrumental Specificity: Leveraging High-Resolution Mass Spectrometry (HRMS) provides an unrivaled level of specificity. Instruments like the SCIEX 7600 system can use a narrow mass window to "zero in" on the exact mass of a target analyte to the fourth decimal place, effectively filtering out isobaric interferences that would confuse a standard triple quadrupole instrument. Holly also gave a shout-out to the NIST PFAS Interference List (PIL), a valuable, free resource for identifying known interferences in food matrices.

The Hidden Danger of Masked Mycotoxins

The conversation also shed light on a lesser-known but significant food safety issue: masked mycotoxins. Holly explained that plants, as a defense mechanism, metabolize mycotoxins into conjugated forms. While these "masked" versions are less toxic, the danger arises upon human ingestion.

"There have been quite a bit of studies reporting their conversion back to the toxic compounds... through gut metabolism," she noted. The problem is that these compounds are largely unregulated and not routinely screened for, meaning we don't understand the full extent of our exposure or the health risks involved. This highlights the urgent need for sensitive and selective methods that can profile all naturally occurring toxins in our food.

Optimizing the Modern Lab for Efficiency and Sustainability

Looking forward, Holly discussed several key trends for improving laboratory workflows. She is a strong advocate for a "less is more" approach to sample preparation, such as direct injection or simple dilution, which saves time and reduces contamination risk if instrument sensitivity allows.

Other impactful improvements include:

Automation: Automated sample preparation is becoming increasingly popular, freeing up scientists' time for more critical work while improving data reproducibility.
Leveraging Software: Holly, who previously worked in software R&D, encourages users to explore the full capabilities of their instrument software. Many built-in features for batch management, data processing, and complex calculations are underutilized and can significantly increase efficiency.
Sustainability: "Green" lab practices are a dominant emerging theme. The focus is shifting toward miniaturization (e.g., micro-SPE), reducing solvent waste, and decreasing sample volumes without compromising data quality.

Ultimately, Holly’s insights painted a picture of an industry in constant motion. From being creative with existing tools—like combining different column chemistries to create a "mixed-mode environment" for broad PFAS panels—to embracing automation and AI, the modern analytical lab is a hub of dynamic problem-solving. It was a powerful reminder that behind every clean food label and safe environmental standard is a community of dedicated scientists pushing the boundaries of detection.

Additional Resources

Learn More:

Visit SCIEX to learn more about trace-level detection and quantification of PFAS and mycotoxin testing for food safety
Explore SepScience.com for chromatography education and training modules

Connect with Sean:

LinkedIn: Holly Lee
LinkedIn: David Oliva

About This Episode: