Emerging Contaminants Summit
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Emerging Contaminants Summit
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Charles Neslund Charles Neslund
Scientific Officer
Eurofins Lancaster Laboratories Environmental

Mr. Neslund is the Scientific Officer for Eurofins Lancaster Laboratories Environmental, LLC. He is responsible for identifying and framing trends in analytical testing and equipment. He communicates the technical needs of the environmental market and our clients to the technical director in order to initiate new methodology for research and development. He is the subject matter expert for HRMS as well as the subject matter expert for testing of PFAS compounds in various matrices. He has over 33 years of laboratory experience. He has a B.S. in Chemistry from the University of Pittsburgh (1982) and two years of graduate study.



WORKSHOP PRESENTATION

Lessons Learned from the Application of Total Oxidizable Precursors (TOP) Assay on Environmental Samples

One of the approaches to assessing the hidden mass of PFAS is based on the transformation to the terminal acids that can be facilitated as described by Erika Houtz and David Sedlak (Environ. Sci. Technol. 46, 9342-9349 (2012)). The oxidation process described yields an estimation of the total oxidizable precursors present in a given environmental sample. The process has been has been deployed in our laboratory and others as one tool available to assess the hidden mass. However, in the course of applying the technique to environmental samples, several hurdles have been encountered based on a variety of parameters observed in environmental samples. Some of these hurdles have suggested limitations in the application of the TOP assay, but really may be emblematic of the extension of the application to matrices not foreseen by the authors. The incorporation of additional parameters allows the analyst to assess the “goodness” of the analytical product, but potentially more important, may allow one to optimize the reaction conditions to sample matrix types. The presentation will describe many of the problems seen with the application of the TOP assay to a wide range of matrices Additionally, a contrast of the validation data to several sample types will be presented along with the measures taken and adjustments made within the analytical protocol to improve the effectiveness of the results that are generated.


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