EPA Method 537.1 is a specialized analytical technique for detecting selected per- and polyfluoroalkyl substances (PFAS) in drinking water. Renowned for its precision and reliability, this method is crucial for assessing water safety and environmental health.
Discover EPA Method 537.1 for PFAS testing in drinking water – essential for environmental consultants and homeowners concerned about water purity.
In this article, we explore the nuances of EPA Method 537.1, detailing its significance and applications in PFAS analysis.
Read our other articles about PFAS test methods:
TOF Assay
Modified EPA Method 537
Overview of EPA Method 537.1
EPA Method 537.1 is a highly accurate and sensitive method for detecting a specific set of per- and polyfluoroalkyl substances in drinking water. Utilizing liquid chromatography-tandem mass spectrometry (LC-MS/MS), it is designed to identify and quantify these compounds with high precision.
Developed in response to the growing need for reliable PFAS detection in environmental and public health contexts, EPA Method 537.1 represents a significant advancement over earlier methods, offering enhanced sensitivity and a broader range of detectable PFAS compounds. This method was specifically tailored to address the complexities associated with PFAS analysis in drinking water, reflecting evolving scientific understanding and regulatory requirements.
In practice, EPA Method 537.1 is widely used across various fields. Environmental scientists employ it for monitoring and research purposes, particularly in studying the presence and concentration of PFAS in water sources.
Public health officials rely on this method to assess potential risks associated with PFAS in drinking water, informing safety standards and public health advisories. In the industrial sector, it is instrumental for ensuring compliance with environmental regulations, especially in industries known to use or discharge PFAS.
The method’s accuracy is crucial, capable of detecting PFAS at low concentration levels, thus providing reliable data for making informed decisions. Its sensitivity to a wide range of PFAS compounds, including some short-chain varieties that are more challenging to detect, makes it an invaluable tool for comprehensive water quality assessments.
Read my article on Analytical methods for PFAS for additional details.
List of Analytes for EPA Method 537.1
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 |
EPA Method 537.1 Technical Details
Procedure and Process
EPA Method 537.1 employs a detailed and systematic procedure using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the analysis of PFAS in drinking water. The process begins with the collection of a water sample, which is then passed through a solid phase extraction (SPE) to concentrate the PFAS compounds. The concentrated sample is subsequently analyzed using LC-MS/MS, where PFAS compounds are separated, identified, and quantified.
This method is notable for its use of isotope dilution, a technique that enhances the accuracy of quantification by compensating for matrix effects and recovery variability. The precision of LC-MS/MS, combined with the specificity of the SPE process, provides EPA Method 537.1 with a high degree of accuracy and sensitivity, setting it apart from other PFAS testing methods.
Learn more about EPA’s efforts in PFAS analysis in drinking water on their official PFAS methods page.
Accuracy and Sensitivity
The accuracy and sensitivity of EPA Method 537.1 are among its most significant features. The method is capable of detecting PFAS compounds at very low concentration levels, often in parts per trillion, making it highly reliable for monitoring trace levels of these substances in drinking water.
The use of isotope dilution and the specificity of the LC-MS/MS analysis contribute to the method’s high sensitivity, enabling the detection and accurate quantification of a broad spectrum of PFAS compounds, including those that are more challenging to detect.
Comparison with Other Methods
EPA Method 537.1 offers distinct advantages in PFAS detection compared to other methods. Below is a table comparing EPA Method 537.1 with other PFAS testing methods, highlighting its specific strengths and potential limitations.
| Method | Advantages | Disadvantages |
| EPA Method 537.1 | High sensitivity for drinking water; broad PFAS range | – |
| EPA Method 533 | Effective for short-chain PFAS | Limited PFAS compound range |
| TOP Assay | Broad spectrum analysis; captures all PFAAs | Non-standardized; less specificity |
| ASTM D7979 | Suitable for various matrices | Higher detection limits compared to 537.1 |
| ASTM D7968 | Efficient for soil analysis | Limited to soil; less suitable for water
|
Access detailed information on EPA Method 537.1 in the EPA’s public record.
Practical Implications for EPA Method 537.1
For Environmental Consultants
EPA Method 537.1 is a cornerstone in the toolkit of environmental consultants, particularly for projects involving the assessment of PFAS in drinking water. Its application is crucial in conducting site assessments, especially in areas with suspected or known PFAS contamination.
The method’s precision and ability to detect a wide range of PFAS compounds make it invaluable for regulatory compliance testing and in developing effective remediation strategies. Environmental consultants rely on EPA Method 537.1 to provide accurate data for environmental impact studies, aiding in the formulation of informed decisions and recommendations for environmental cleanup and management projects.
For Homeowners
For homeowners, especially those in areas near industrial sites or regions with known PFAS usage, EPA Method 537.1 can be a key resource in assessing the safety of their drinking water.
This method’s ability to accurately detect and quantify PFAS compounds offers peace of mind and is essential for those concerned about the quality and safety of their water supply. Homeowners can use the results from this testing method to make informed decisions about water filtration systems, property values, and overall health and safety measures for their families.
Cost and Accessibility
The cost and accessibility of EPA Method 537.1 can vary, with factors such as the complexity of the testing and the laboratory performing the analysis influencing the overall expense. While this method involves advanced analytical techniques, it is increasingly available through environmental testing laboratories, making it accessible to both consultants and homeowners.
For homeowners, the cost may be a consideration, especially for comprehensive testing, but the investment is often justified by the method’s thoroughness and reliability. For environmental consultants, the method’s efficiency and accuracy offer cost-effective solutions for large-scale and detailed PFAS analysis projects.
Explore Agilent’s overview of US EPA Method 537.1 for water analysis applications.
Final Take
EPA Method 537.1 emerges as a crucial analytical method for the accurate detection and quantification of PFAS in drinking water, serving the needs of both environmental consultants and concerned homeowners. Its technical precision in identifying a wide range of PFAS compounds, combined with its high sensitivity, makes it invaluable for assessing water safety and environmental health. The method’s accessibility and reliability, despite potential cost considerations, underscore its importance in addressing the challenges of PFAS contamination in residential and public water supplies.