Professor Detlef Knappe

♪ [music] ♪ My name is Detlef Knappe and I'm a professor of civil construction and environmental engineering at North Carolina State University in Raleigh, North Carolina.

One important focus of our research is to develop analytical methods to characterize the quality of our drinking water. And this research is motivated by the question that a lot of people ask us. And that is, "Is the water safe to drink?" And, not until too long ago, it was okay to answer this question by saying the water quality meets all regulations. But over the last few years, it's become abundantly clear to the public that there are many contaminants in our drinking water that are unregulated.

So, there is a lot of concern about our exposure to contaminants about which we don't know whether they're present in our water or not. And to help answer that question, we really need analytical methods that allow us to dig deeper and understand what contaminants are present in our drinking water.

Key examples of unregulated contaminants we focus on in our research are the per- and polyfluoroalkyl substances, or PFASs, which is a class of thousands of individual chemicals. And current analytical methods that the EPA has published for the characterization of drinking water only target 29 of the thousands of PFASs that are out there.

So, an important goal of our research is to develop more comprehensive analytical workflows to characterize PFAS contamination in our drinking water. When it comes to PFAS exposure, we're very interested in understanding not just the route of exposure through drinking water, which can be very important, but also other routes of exposures, such as ingestion of contaminated food or inhalation of contaminated air.

So, in that respect, we're very interested in developing sampling strategies for the characterization of air, and also extraction methods to help us comprehensively characterize PFAS levels in food and in air.

The results of this work will then help us better understand the relative source contributions of exposure. In terms of impacts of our work, the characterization of PFAS in drinking water have led to the identification of PFAS sources. And, in the meantime, the source of that contamination has been reduced dramatically. So, as a result, PFAS levels in the drinking water of communities that were previously impacted have dropped substantially.

In our work to develop analytical methods, we rely, at times, on the expertise of application scientists at Agilent. A good example here is when we were developing an analytical method for 1,4-Dioxane. We wanted to combine this method with a very comprehensive method to determine volatile organic contaminants in water, because 1,4-Dioxane commonly co-occurs with volatile organic contaminants.

And when we were developing this method, we ran into an issue of a particular volatile organic contaminant interfering with our 1,4-Dioxane internal standard. And we got some very helpful advice from an application scientist at Agilent who help us resolve this interference. And that is currently a method that we're planning to publish together, with Agilent. ♪ [music] ♪