The Biggest Analytical Challenges in PFAS Testing

Per- and polyfluoroalkyl substances (PFAS) present a unique analytical problem for scientists today. It’s unknown exactly how many PFAS currently exist in the environment, which can make detection using traditional separation methods a challenge. In addition to the numerous hazards PFAS present to human health, these forever chemicals can also present contamination problems when testing samples. PFAS can be introduced into samples through laboratory equipment, if not properly cleaned and tested.

Tarun Anumol is the global environment market manager for Agilent Technologies.

Instrument manufacturers are working in tandem with laboratory scientists to find better methods for PFAS analysis. Tarun Anumol, global environment market manager for Agilent Technologies, spoke with LCGC International about how the company is addressing these challenges with its clients.

Where is most of the PFAS testing happening today?

The bulk of the PFAS testing currently is happening on the environmental water analysis side. And then within that, there is more testing happening in drinking water than wastewater. Although more testing is happening on the wastewater side as we get new regulations. There's more push to hold both industry and manufacturers accountable. Regulations always spur testing demand, but since it’s become a public policy issue there is a lot of demand for more PFAS testing.

There’s also a geographical component. In the U.S., a lot of the testing is happening on water, but we’re also starting to see some regulations on the consumer products side. For example, carpets, or textile analysis. In the European Union, there’s a lot more testing happening on the food side, and that’s translating to testing in Asia because of import and export. There’s also a lot of PFAS testing happening in Asia on the raw materials and on the manufacturing side.

What are the biggest analytical challenges that we're seeing today when it comes to testing and identifying PFAS?

There are five different challenges with PFAS when we look at it from a macro scale. We use PFAS in almost everything. They are everywhere. One of the biggest issues when you're analyzing PFAS in a laboratory is making sure you don't have PFAS in the measurement background. You really must ensure that you're doing good practices in the laboratory. You must be certain you are not using things that are potentially contaminated with PFAS.

The second challenge is the sensitivity. We have not had any chemicals, at least in the U.S., that have been regulated even close to 100 times the level of PFAS. Most regulations for pesticides and semi volatile compounds are in the low parts per million (ppm) level. Because of this it’s important to have good laboratory practice and to make sure you're measuring much lower, so you must focus a lot more on cleanliness.

The third issue with PFAS is the scope. What a lot of these laboratories are struggling with is that almost every month there's a new PFAS compound that is found, or there's a new list of PFAS that a regulator puts out, or a new analytical method that has different PFAS. We’ve gone from, probably 10 years back, testing for just 2 PFAS, to having some regulatory methods from the U.S. Environmental Protection Agency (EPA); that came with 10, and then 14, and then 40 different compounds.

The list keeps going up. For laboratories now, not only do they have to think about measuring PFAS now, but they also have to future proof the laboratory. They must be like, “Okay, we're going to have to add a lot more PFAS in time. How do we go about doing that?” They need to think about the analytical instruments, what they're getting, whether it's future proof, whether it can last a few more years.

The fourth issue with PFAS is really the amount of unknown PFAS. Currently, we have analytical standards only available for approximately 100 PFAS, and our regulatory agencies are only looking at somewhere around 100 PFAS. But we don't even know how many PFAS there are in the environment. We are only looking at 1–2% of all PFAS right now, so how do you close that gap? Whether you use higher resolution mass spectrometry (MS) tools like quadrupole time-of-flight mass spectrometry (QTOF-MS) to identify some of those, or whether you use bulk characterization, for example inductively coupled plasma–mass spectrometry (ICP-MS) or a combustion ion chromatograph (CIC) to measure the total organic fluorine (F) in the sample. That's a big analytical challenge and it requires multiple techniques to get a true characterization of the sample.

The last challenge on PFAS, is not so much just limited to an analytical laboratory, but it's related to how you report data. How do you report PFAS data, not only to your stakeholders but even to the public? Because there's so much interest. A lot of people want to send their water samples to an analytical laboratory from their well. I think there's a science communication issue in PFAS that also comes onto the vendors, because it makes it more inherent that we explain how this testing is done, and how the analytical instruments are used to do the test.

How does Agilent limit PFAS in its own manufacturing processes and for its customers?

One of the things we’ve done is we went back to our manufacturing process and looked at our entire instrument lineup, searching for any potential place where PFAS might be going into those systems. We have things that we know that we can replace now on a system.

We don't knowingly use any PFAS in the manufacturing of the instruments. What happens is, they can come in from certain impurities. For example, PFAS can be a common impurity in fluoropolymer. What we did is we went back and looked at where we use fluoropolymers on the instruments. Then we replaced a lot of those parts that we provide as part of our PFAS free testing kits, but also, we make those changes in the instrument.

The second thing that we've done is we've very proactively worked with regulators to work on standardized methods. That can involve working with the EPA–and we've been part of the multi-laboratory validations for EPA 1633 and EPA 537–but we've also very actively worked with standards and consensus organizations like ASTM ISO. We put a lot of technical resource and background into this. We have 17 people in North America that have either worked directly with or worked for the U.S. EPA or a state regulatory agency. That's a lot of expertise that we can factor into PFAS testing for these environmental laboratories, because we have people that have done it in the laboratories themselves.

Beyond that, there's also a large sustainability component. In terms of our manufacturing and quality teams, we are looking at a lot of our packaging materials and making sure they are free of PFAS. We don't want to support the testing only to find out that we are contributing to the problem. So, there's a lot of work happening with our Quality Assurance and Regulatory teams to make sure we minimize any potential, even unintended impacts, of PFAS usage on our sites as well.

What are your clients’ biggest concerns when it comes to PFAS testing right now?

One thing that we've really seen is the shift in the environmental and food industry, as in the skill level of operating the instrument has gone down. I'm not saying the skill level of the person has gone down, but they have so many other tasks to do now. They don't really want to focus on tuning the instrument manually, cleaning it manually, and learning what each piece does. What they really want, and need is something that can get them the answer in the fastest and most reliable manner. So, we have focused on making our workflows basically like a plug-and-play or press-buttons-and-go process.

We've done a lot of things on the instrument side. For example, we've added Autotune, which basically tunes the instrument system quickly. We've added Intelligent Reflex, which is basically an early maintenance feedback (EMF) system where the instrument now can tell, based on all its internal sensors, the customer some of the things that may potentially be going wrong. What we've done is we've created a lot of the reporting and data analysis, so that the customer doesn't have to spend a lot of time figuring that out.

We've even incorporated artificial intelligence (AI) into the process. We have a proprietary AI company that we purchased to look at integration, but then on the back-end reporting, what we've done is we've created the templates that are specific to the EPA methods based on what the EPA wants. So, we've worked with customers to create those templates so that you get a standardized report form. This goes back to what I talked about with communication as well. If you're producing standard templates in all the laboratories and monitoring how the data is reported, that's one less step you must take to communicate to the public or other groups. We're doing a lot of those sorts of things to simplify the tasks for laboratory analysts, so that they are just focusing on getting their samples to the instrument, and then everything else is automated.

Are there any future trends that you expect we will see in PFAS analysis?

Some of the research studies are showing more and more that we've vastly underestimated the volatile component of PFAS. I expect more and more testing for PFAS to happen on air quality measurements. As we also look to remediate and destroy these PFAS, especially with thermal destruction techniques, you’ll have more products of incomplete combustion (PICs) released into the atmosphere. I expect significantly more volatile PFAS testing with GC–MS to happen.

I also see continuous public demand and regulations for PFAS in consumer products. I can also see PFAS testing moving into the pharma space with tablets and other medications, and making sure raw pharma materials are PFAS-free as we learn more about the potential health effects of PFAS.

This interview has been lightly edited for length and clarity.