PFAS Testing in Drinking Water
Eurofins performs PFAS analysis in drinking water by EPA Method 537 v1.1 which uses Solid-Phase extraction (SPE) with liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis. Samples are collected in 250 mL plastic bottles fitted with a plastic screw-cap. All sample containers include 5 grams/L of Trizma which serves as a buffering agent and to remove free chlorine that may be present in the sample. In addition to sample containers, Eurofins also includes supplies for collecting field reagent blanks (FRBs). The FRBs are prepared by Eurofins and include a preserved container filled with reagent grade water and an empty unpreserved container to pour the blank water into in the field at the time a sample is collected. FRBs are required by the method but the number of field blanks to collect (for each site, for each representative sample or not at all) is at the discretion of the customer and/or regulator overseeing the project.
In September of 2016, EPA issued a Technical Advisory informing of the possible under-reporting of PFOA when adhering to EPA 537 as originally written and recommending expansion of the integration window to account for branched isomers of PFOA. Many of the PFASs can occur in the environment as both branched and linear isomers. However, only a linear standard is currently available for PFOA. The original EPA-approved method did not account for both types of isomers because doing so requires chromatographic peak integration of samples to be calibrated in the same way as the calibration standard, resulting in a limited integration window.
Eurofins now includes branched PFOA isomers in the quantitation of PFOA. We can quantify and report the following PFAS compounds:
Standard List – Method 537
| Parameter | CAS # | Reporting Limit |
| N-ethyl Perfluorooctanesulfonamido- acetic acid (NEtFOSAA) | 2991-50-6 | 2 - 2.5 ng/L |
| N-methyl Perfluorooctanesulfonamido- acetic acid (NMeFOSAA) | 2355-31-9 | 2 - 2.5 ng/L |
| Perfluorobutanesulfonic acid (PFBS) | 375-73-5 | 2 - 2.5 ng/L |
| Perfluorodecanoic acid (PFDA) | 335-76-2 | 2 - 2.5 ng/L |
| Perfluoroheptanoic acid (PFHpA) | 375-85-9 | 2 - 2.5 ng/L |
| Perfluorohexanesulfonic acid (PFHxS) | 355-46-4 | 2 - 2.5 ng/L |
| Perfluorohexanoic acid (PFHxA) | 307-24-4 | 2 - 2.5 ng/L |
| Perfluorolauric acid (PFDoA) | 307-55-1 | 2 - 2.5 ng/L |
| Perfluoromyristic acid (PFTA) | 376-06-7 | 2 - 2.5 ng/L |
| Perfluorononanoic acid (PFNA) | 375-95-1 | 2 - 2.5 ng/L |
| Perfluorooctane sulfonate (PFOS) | 1763-23-1 | 2 - 2.5 ng/L |
| Perfluorooctanoic acid (PFOA) | 335-67-1 | 2 - 2.5 ng/L |
| Perfluorotridecanoic acid (PFTrDA) | 72629-94-8 | 2 - 2.5 ng/L |
| Perfluoroundecanoic acid (PFUnA) | 2058-94-8 | 2 - 2.5 ng/L |
Extended List – Method 537
| Parameter | CAS # | Reporting Limit |
| ADONA | 958445-44-8 | 2 - 2.5 ng/L |
| F-53B Major | 73606-19-6 | 2 - 2.5 ng/L |
| F-53B Minor | 83329-89-9 | 2 - 2.5 ng/L |
| GenX | 13252-13-6 | 5.0 ng/L |
| N-ethyl Perfluorooctanesulfonamido- acetic acid (NEtFOSAA) | 2991-50-6 | 2 - 2.5 ng/L |
| N-methyl Perfluorooctanesulfonamido- acetic acid (NMeFOSAA) | 2355-31-9 | 2 - 2.5 ng/L |
| Perfluorobutanesulfonic acid (PFBS) | 375-73-5 | 2 - 2.5 ng/L |
| Perfluorodecanoic acid (PFDA) | 335-76-2 | 2 - 2.5 ng/L |
| Perfluoroheptanoic acid (PFHpA) | 375-85-9 | 2 - 2.5 ng/L |
| Perfluorohexanesulfonic acid (PFHxS) | 355-46-4 | 2 - 2.5 ng/L |
| Perfluorohexanoic acid (PFHxA) | 307-24-4 | 2 - 2.5 ng/L |
| Perfluorolauric acid (PFDoA) | 307-55-1 | 2 - 2.5 ng/L |
| Perfluoromyristic acid (PFTA) | 376-06-7 | 2 - 2.5 ng/L |
| Perfluorononanoic acid (PFNA) | 375-95-1 | 2 - 2.5 ng/L |
| Perfluorooctane sulfonate (PFOS) | 1763-23-1 | 2 - 2.5 ng/L |
| Perfluorooctanoic acid (PFOA) | 335-67-1 | 2 - 2.5 ng/L |
| Perfluorotridecanoic acid (PFTrDA) | 72629-94-8 | 2 - 2.5 ng/L |
| Perfluoroundecanoic acid (PFUnA) | 2058-94-8 | 2 - 2.5 ng/L |
Due to occurrence information that is emerging as a result of post UCMR monitoring, there is now much more interest in compounds not on the original EPA 537 list.
Related Links
Centers of Excellence
Eurofins Lancaster Laboratories Environmental
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