Per- and Polyfluorinated Alkyl Substances (PFAS)
Per- and Polyfluorinated Alkyl Substances (PFAS) chemical compounds are a class of emerging contaminants that are generating high levels of interest and concern in the environmental community and the public at large. These compounds have a wide range of industrial uses and commercial product applications and are present in many consumer products as well. A short list of general product categories includes industrial polymers, stain repellents, waterproofing products, surfactants, and packaging, as well as aqueous film-forming foams (AFFF) used for firefighting. The primary sources of PFAS released into the environment can be industrial facilities where they were used or contained in raw material feedstocks; as well as sites where AFFF was used for training purposes or actual firefighting. Other potentially significant sources of PFAS are landfills and wastewater treatment plants. PFAS compounds are highly soluble in water, chemically stable and persistent. Practitioners are cautioned to carefully consider potential sources of PFAS cross-contamination in the design of their sampling programs and sampling standard operating procedures (SOPs). There is considerable information available online from regulators and academia that provide recommendations to minimize potential sources of cross-contamination in a wide range of items, from clothing and personal care products to sampling equipment. For more information regarding recommended sampling techniques, please download Alpha Analytical’s PFAS Sampling Instructions for potable and non-potable water.
Alpha Analytical currently offers PFAS analytical support utilizing a number of different procedures depending on your project application.
Drinking Water-Related Applications
Alpha Analytical has considerable experience with drinking water and we offer PFAS analysis in accordance with EPA Method 537.1 and the newly released EPA Method 533. Method 533 differs from 537.1 in that it incorporates an isotopic dilution approach using extracted internal standards as part of its calibration requirements as well as other method performance upgrades. While Method 537.1 specifies a list of 18 PFAS compounds, Method 533 specifies a 25 target compound list, either of which can be reported in their entirety, or as a subset. While there is substantial overlap between the two lists, not all of the 18 Method 537.1 compounds are listed under Method 533. For more information on EPA Method 533, visit our website.
Since Methods 537.1 and 533 are limited to clean water applications, Alpha Analytical uses a different procedure for the testing of non-potable water, soils and tissue samples. This method is particularly effective in cases where there are additional, specific PFAS compounds that need to be included that are not on either method’s target compound list. Given the lack of standardized, published analytical methods for non-drinking water sample media, and the fact that EPA 500 series methods are not allowed to be modified in this way, Alpha Analytical has developed its own procedure.
This method is also a liquid chromatography tandem mass spectrometry method (LC/MS/MS) with solid phase extraction (SPE) and it is similar to the LC/MS/MS SPE Method 533 in that it also utilizes the isotope dilution technique. Alpha Analytical incorporates the maximum number of commercially-available extracted internal standards, consisting currently 25 13C-enriched and 2 2H-enriched compounds. (As more of these reference standards become available, they will be incorporated into our method as well. We are currently analyzing for up to 41 PFAS compounds, or any subset, using this approach.) We analyze a wide range of sample matrices in addition to aqueous samples including soils/sediments, biosolids, tissues, and food/ agricultural products such as milk and cranberries. Given our laboratory’s extensive background supporting ecological risk assessments, we also have considerable experience with the processing of fish, shellfish, soils and sediments.
We also perform the total oxidizable precursors (TOP) assay on aqueous samples. The TOP assay is an analysis by difference approach, where two aliquots of a sample are analyzed. One aliquot is pre-treatment and the other is post-treatment, with the latter subjected to strong oxidizing conditions prior to PFAS analysis. The PFAS concentration difference between the pre- and post-treatment samples is defined as the amount of oxidizable precursors present in the sample.
Alpha is currently operating four LC/MS/MS instruments. We also have 14 PFAS-dedicated solid phase extraction manifolds and our standard turnaround time is 10 business days. Alpha currently holds National Environmental Laboratory Accreditation Conference (NELAC) certifications for both Method 537.1 and Method 533, as well as our proprietary isotope dilution method in addition to many state certifications for PFAS analysis. Alpha is also certified by the Department of Defense Environmental Laboratory Accreditation Program (DoD ELAP) for Method 537.1, Method 533 and the isotope dilution method.
To find out how we can help with your upcoming emerging contaminants sampling program, contact Alpha Analytical today. We offer PFAS, 1,4-Dioxane, Perchlorate, and 1,2,3-Trichloropropane analytical support.
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