Per- and polyfluoroalkyl substances (PFAS), often labeled as "forever chemicals," have become one of the major analytical challenges facing environmental laboratories. Their chemical persistence, widespread application in consumer and industrial products, and potential toxicity at ultra-trace levels demand innovative solutions for accurate detection and quantification. In a recent interview for the Concentrating on Chromatography podcast, Edward Faden, Vice President and co-owner of MAC-MOD Analytical, discussed the realities of PFAS analysis in the laboratory and how MAC-MOD is helping chemists overcome these hurdles.
Watch the full interview here: https://www.youtube.com/watch?v=fCIGumZJW4s
The Pervasiveness of PFAS
PFAS have been in widespread use since the 1940s—found in waterproof clothing, upholstery treatments, non-stick cookware, food packaging, and firefighting foams. Their chemical stability means they do not readily degrade in the environment, persisting in water, soil, and living organisms, often accumulating over time. As Edward Faden explains, “These compounds are everywhere... their use in so many applications led to widespread entry into the natural environment. Today, labs need to quantify them at parts-per-trillion levels, which even parts-per-billion is challenging for most.” PFAS contamination is difficult to avoid, not only in the field but also in the controlled environment of the laboratory.
Uncovering Hidden Sources of Laboratory PFAS Contamination
During the development of an LC-MS/MS method to analyze PFAS according to EPA 537.1, MAC-MOD partnered with Avantor’s research lab in the UK to screen commonly used materials and consumables. Routine lab items—tissues, tinfoil, gloves, sticky tape—were found to leach detectable PFAS into organic solvent extracts. Even certain brands of vial caps were identified as a source of extractable PFAS, while alternatives showed no contamination. The method development process highlighted the importance of meticulously testing and excluding product lines known to introduce PFAS.
Perhaps most revealing was the discovery of PFAS contamination stemming from the laboratory’s gas lines: nylon tubing supplying the nitrogen generator was leaching short-chain PFAS into samples during nitrogen blowdown. By switching to a nitrogen cylinder with polypropylene tubing, this critical source of contamination was eliminated. As Faden points out, “This example demonstrated for us how challenging PFAS analysis can be. Eliminating sources of contamination is a big issue people face.”
Innovations: The PFAS Delay Column
One of the most significant technological advances highlighted in both the poster and the interview is the use of a PFAS delay column—a specialized mini-column installed just before the analytical column in the HPLC system. Many LC components (solvent lines, degasser membranes, etc.) can shed trace PFAS into the mobile phase, which then accumulates on the analytical column and coelutes with analytes during gradient runs. Edward explains, “The delay column is like an additional column that we install immediately before the sample injector so that background PFAS are trapped and separated from those in the sample.”
MAC-MOD’s and Avantor ACE PFAS delay columns employ a highly retentive reversed-phase packing material to maximize separation of system-derived PFAS. This innovation is crucial—blank system gradients without samples injected revealed five common PFAS just from instrument components. While specialized solvents and buffer grades minimize risk, only the delay column provides reliable separation of background contaminants from analyte PFAS.
Best Practices for Labs Starting PFAS Analysis
Drawing from MAC-MOD’s research and Edward’s experience, several best practices emerge for laboratories new to PFAS testing:
- Install a delay column and use high-quality, PFAS-grade solvents to minimize background interference.
- Screen all consumables (including gloves, vials, pipette tips, bottles) for PFAS, even if previously vetted, as manufacturing or packaging changes can introduce new risks.
- Replace system components (tubing, fittings, manifolds) with PFAS-free materials like polypropylene.
- Dedicated glassware and avoiding communal cleaning by laboratory glass washers can further prevent cross-contamination.
- Routinely run blanks and prescreen solvents, buffers, and new consumable batches.
Laboratories are also encouraged to work directly with vendors who provide sample preparation platforms specially developed for PFAS analysis. Organomation’s PFAS-free N-EVAP evaporator is a practical option for nitrogen blowdown, provided users optimize gas sources and line materials.
Learn more: Waters Corporation Utilizes Organomation N-EVAP to Concentrate PFAS Samples
Rapid Sample Pre-Screening: A New Frontier
MAC-MOD is pioneering a rapid sample pre-screening strategy to further address the risk of cross-contamination between samples of highly variable PFAS load. Their new 10 mm high-throughput mass spec column can separate 18 PFAS and 7 internal standards in a 62-second gradient, compared to traditional methods requiring 10-30 minutes. This enables labs to quickly identify and segregate high-contamination samples—protecting overall workflow integrity.
Looking Ahead: Unique Chemistries and Innovative Solutions
MAC-MOD continues to innovate with unique stationary phase chemistries beyond the standard C18, developing C18-PFP and similar solutions that further optimize separation between critical PFAS peak pairs. Their specialized focus and extensive QA protocols ensure that each HALO® PFAS or delay column lot is tested for reproducible performance over a broad range of compounds.
Edward sums up MAC-MOD’s philosophy: “We offer some truly great solutions and encourage labs to pay attention to our very innovative technologies—we’ve got a lot on the docket for the future.”
PFAS analysis is an extraordinarily demanding undertaking, but with diligent workflow management, rigorous consumables screening, and the adoption of advanced technologies such as delay columns, laboratories can achieve reliable, reproducible results at trace levels. MAC-MOD’s research and product innovations address the real-world challenges chemists encounter and enable environmental laboratories to meet regulatory targets with confidence.
Ready to streamline sample concentration for PFAS analysis?
To learn more about Organomation’s PFAS-free nitrogen evaporators and how we support contamination-free workflows, contact our technical team today.
For additional details on the research and podcast episode, check out https://www.youtube.com/watch?v=fCIGumZJW4s