The discovery of 17 previously unreported PFAS in chemical wastewater highlights the evolving challenges in detecting and understanding these persistent contaminants. Karl Oetjen, PhD, market development manager at SCIEX, discusses how non-targeted analysis using high-resolution mass spectrometry enabled this breakthrough. He explores the broader implications for wastewater systems, food safety, and public health while emphasizing the role of laboratory managers in advancing PFAS research. Additionally, Oetjen shares insights on emerging analytical techniques, the future of PFAS detection, and key considerations for laboratories developing PFAS testing capabilities.

What led to the discovery of the 17 previously unreported PFAS in chemical wastewater, and what methods were used to detect these compounds? 

There are thousands of PFAS compounds in use. Traditionally, targeted approaches are used, but these methods only monitor for compounds we are aware of (the known-knowns), around 30-40 compounds.

In comparison, a non-targeted method is where we look for things we don’t know or know we don’t know (the unknown-unknowns and the known-unknowns). This approach was used to identify these 17 previously unreported PFAS using liquid chromatography and high-resolution mass spectrometry. In addition to this, using SWATH DIA increases the amount of MS/MS data, increasing the ability to identify characteristic ions leading to the discovery of new compounds and added confidence during identification.

How does this discovery change our understanding of PFAS contamination, particularly in wastewater systems? Can you elaborate on how this discovery could directly impact food safety and public health? 

Processing non-targeted data is typically laborious, as a complex sample may contain thousands of irrelevant features. Sorting through these data to discover novel PFAS compounds can, therefore, become a manual, time-consuming process. Professor Si Wei and his team at Nanjing University's School of Environment in China developed a new machine-learning platform to automate these processes, leading to the discovery of 17 new PFAS in wastewater samples. Identifying which PFAS compounds are present in our bodies is crucial for toxicology studies. Moreover, once these compounds are detected in humans and their health risks are understood, we can begin to ask the question: “Where did these compounds come from—our food, water, air, or elsewhere?”

What role can laboratory managers play in supporting regulators to address these emerging contaminants? 

Laboratory managers can support this process through constant innovation. It’s important to collaborate and share innovative methods and findings so that PFAS analysis can continue to expand so that one day, we can hopefully understand the true situation of how the PFAS life cycle will impact our health and the environment. 

Professor Wei’s study found these novel PFAS compounds from a fluorochemical plant. We know that the PFAS life cycle means that if left untreated, this wastewater can emit into surface water, and potentially into drinking water. 

What advancements in analytical chemistry do you anticipate will further enhance our understanding and mitigation of PFAS in the future? 

In my opinion, as demonstrated by Si Wei, some of the most significant advancements in analytical chemistry will stem from HRMS and, equally importantly, from the ways in which we process these datasets. For decades, we have had access to high-quality datasets and samples, but we lacked the tools to fully process and interrogate them. Additionally, the widespread adoption of HRMS has led to the creation of large spectral libraries, making it substantially easier to more thoroughly characterize samples. These libraries will only continue to increase as HRMS workflows become more common. 

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What advice would you give to labs that are just starting to develop PFAS testing capabilities? 

For many testing laboratories, being prepared and producing results within a timeframe is key. Automation is becoming a true differentiator for labs that may have high sample quantities to run. For many municipalities, such as those testing water samples, it’s important to have resources ready to prepare samples. Running a sample may only take 10 minutes, but knowing how to prepare it—and then actually doing so—can require hours of manual work. A key piece of advice for all labs is not to underestimate sample preparation. Having validated methods or a partner who can assist can make all the difference.

Additionally, because PFAS contamination is so widespread, laboratories must be patient when troubleshooting its sources and should lean on the PFAS testing community for insights into potential origins of contamination.

Karl Oetjen is a market development manager for Environmental, Industrial, Food & Beverage at SCIEX and has over 10 years of mass spectrometry experience. Before joining SCIEX, he completed his PhD at Colorado School of Mines (Golden, Colorado) in Hydrologic Science and Engineering. Since joining SCIEX, Karl has worked with numerous labs creating and implementing both regulated and unregulated quantitative and qualitative screening methods.