The Modified EPA Method 537 is a pivotal tool in the analysis of PFAS compounds in environmental samples.
Learn about the Modified EPA Method 537 for PFAS testing – essential for consultants and homeowners concerned about environmental safety.
In this article, we delve into the specifics of this method, exploring its technical details, practical applications, and cost implications for both environmental consultants and homeowners.
Check out our other articles on PFAS testing methods:
EPA Method 537.1
EPA Method 533
Overview of Modified EPA Method 537
The Modified EPA Method 537 is a sophisticated analytical technique designed for the detection and quantification of per- and polyfluoroalkyl substances (PFAS) in various environmental matrices. Its development marks a significant advancement in environmental science, offering a more comprehensive approach to identifying a wide range of PFAS compounds.
Read my article on Analytical methods for PFAS for additional details.
History
Originally developed to address the growing need for accurate PFAS detection in environmental samples, this method has undergone several modifications to enhance its sensitivity and scope. These changes reflect the evolving understanding of PFAS’s environmental impact and the need for more rigorous testing protocols. The Modified EPA Method 537 is particularly notable for its application in analyzing residential water supplies, providing crucial data for assessing water safety and quality.
Accuracy and sensitivity
In various fields, the Modified EPA Method 537 has become a cornerstone for PFAS analysis. Environmental scientists rely on it for monitoring and studying PFAS contamination in ecosystems, while public health officials use it to assess potential risks to human health. In the industrial sector, this method is instrumental in ensuring compliance with environmental regulations and in the development of safer products. Its versatility and precision make it an invaluable tool across multiple disciplines, underscoring its importance in the ongoing efforts to understand and mitigate the effects of PFAS compounds.
Access the full documentation of the Modified EPA Method 537 directly from Chemours’ official file for an in-depth understanding.
List of Analytes for Modified EPA Method 537
EPA Method 537.1 provides accurate results for the compounds listed in the table below.
| Analyte | Acronym | Chemical Abstract Services Registry Number (CASRN) |
| Hexafluoropropylene oxide dimer acid | HFPO-DA | 13252-13-6b |
| N-ethyl perfluorooctanesulfonamidoacetic acid | NEtFOSAA | 2991-50-6 |
| N-methyl perfluorooctanesulfonamidoacetic acid | NMeFOSAA | 2355-31-9 |
| Perfluorobutanesulfonic acid | PFBS | 375-73-5 |
| Perfluorodecanoic acid | PFDA | 335-76-2 |
| Perfluorododecanoic acid | PFDoA | 307-55-1 |
| Perfluoroheptanoic acid | PFHpA | 375-85-9 |
| Perfluorohexanesulfonic acid | PFHxS | 355-46-4 |
| Perfluorohexanoic acid | PFHxA | 307-24-4 |
| Perfluorononanoic acid | PFNA | 375-95-1 |
| Perfluorooctanesulfonic acid | PFOS | 1763-23-1 |
| Perfluorooctanoic acid | PFOA | 335-67-1 |
| Perfluorotetradecanoic acid | PFTA | 376-06-7 |
| Perfluorotridecanoic acid | PFTrDA | 72629-94-8 |
| Perfluoroundecanoic acid | PFUnA | 2058-94-8 |
| 11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid | 11Cl-PF3OUdS | 763051-92-9c |
| 9-chlorohexadecafluoro-3-oxanone-1-sulfonic acid | 9Cl-PF3ONS | 756426-58-1d |
| 4,8-dioxa-3H-perfluorononanoic acid | ADONA | 919005-14-4e |
Modified EPA Method 537 Technical Details
Procedure and Process
The Modified EPA Method 537 involves a detailed procedure designed for the precise detection of PFAS compounds. The process starts with the collection of a 250-mL aqueous sample, which is then fortified with isotopically-labeled extraction standards. These samples undergo solid phase extraction (SPE) to isolate the analytes, followed by elution using a combination of solvents.
The extract is then concentrated and analyzed using LC/MS/MS operated in negative electrospray ionization (ESI) mode. This method’s accuracy is bolstered by the use of isotope dilution for quantitative analysis, ensuring high sensitivity and specificity in detecting a wide range of PFAS compounds.
For more detailed information on EPA’s PFAS drinking water laboratory methods, visit the EPA’s official page.
Accuracy and Sensitivity
The Modified EPA Method 537 is renowned for its high accuracy and sensitivity, making it a reliable choice for PFAS analysis. Its ability to detect low concentrations of PFAS compounds is a critical aspect, especially in scenarios where precise quantification is necessary for health and environmental assessments. The method’s sensitivity is further enhanced by its meticulous extraction and concentration process, ensuring that even trace levels of PFAS are accurately identified and quantified.
Comparison with Other Methods
The Modified EPA Method 537 stands out for its comprehensive approach to PFAS detection. Below is a table comparing it with other PFAS testing methods, highlighting its unique advantages and potential drawbacks.
| Method | Advantages | Disadvantages |
| Modified EPA Method 537 | High sensitivity for a wide range of PFAS compounds; accurate quantification using isotope dilution | More complex procedure requiring specialized equipment |
| EPA Method 537.1 | Specific to drinking water; efficient for certain long-chain PFAS compounds | Limited in detecting short-chain PFAS compounds |
| EPA Method 533 | Effective in capturing short-chain PFAS; suitable for drinking water | May not cover as broad a range of PFAS compounds as Modified EPA Method 537 |
| TOP Assay | Broad spectrum analysis; captures all perfluoroalkyl acids (PFAAs) | Non-standardized, varying methods; less specificity |
| ASTM D7979 | Suitable for various sample types including soil and biosolids | Higher detection limits compared to Modified EPA Method 537
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Understand the differences between various PFAS testing methods, including the Modified EPA Method 537, by reading this insightful Merit Labs blog post.
Conclusion
The Modified EPA Method 537 is a vital tool in the field of environmental science, offering high accuracy and sensitivity for detecting a wide range of PFAS compounds. Its comprehensive approach and advanced analytical techniques make it a preferred choice for both environmental consultants and homeowners concerned about PFAS contamination. This method, with its unique advantages over other testing methods, plays a crucial role in ensuring water safety and environmental health.