This blog is the second of two parts, demonstrating how GERSTEL enables PFAS determination in all matrices of interest. It focuses on the determination of PFAS in water and solid matrices according to EPA methods 533, 537.1, and 1633. To learn more about the full range of GERSTEL’s capabilities for PFAS determination, read part one of our blog series on PFAS in air.
PFAS in Drinking, Waste, Surface and Ground Water; Soils, Biosolids, Tissues, Leachate, and Sediment
The U.S. Environmental Protection Agency (EPA) has developed rigorous testing methods to detect and quantify PFAS in environmental samples. Among these methods, EPA Methods 533, 537.1, and 1633 are key tools in assessing PFAS contamination. The LCTech FREESTYLE™ XANA™ PFAS system, with its advanced capabilities, has proven to be an invaluable asset in effectively determining PFAS levels in compliance with these EPA methods.
Understanding EPA Methods 533, 537.1, and 1633 (Draft 4)
The tables below compare basic method steps and compounds of interest for EPA Methods 533, 537.1, and 1633.
Comparison of EPA Methods 537.1, 533, and 1633
PFAS compounds required for each method
EPA Method 537.1: Determination of PFAS in Drinking Water – 18 Compounds
Introduced in 2018, EPA Method 537.1 builds upon the foundation of Method 537, enhancing its capabilities to include additional shorter-chain PFAS (commonly called “GenX” compounds). It focuses on PFAS drinking water compliance. Method 537.1 utilizes solid-phase extraction (SPE) using a styrene-divinylbenzene (SDVB) phase followed by LC-MS/MS analysis. The method utilizes surrogates to determine recoveries and matrix effects and internal standards to improve precision and accuracy.
EPA Method 533: Determination of PFAS in Drinking Water – 25 Compounds
Published in 2019, EPA Method 533 updates Method 537.1 by removing 4 compounds that were found not to be in drinking water and adding 11 shorter chain (C4-C12) compounds for a total of 25 specific PFAS analytes, including perfluoroalkyl acids (PFAAs) and perfluorooctane sulfonate (PFOS). This method also employs SPE extraction followed by LC-MS/MS analysis but with a weak anion exchange phase. It also includes the use of isotope dilution to improve method accuracy.
EPA Method 1633: Determination of PFAS in Various Matrices – 40 compounds
Released in 2023, EPA Method 1633 (Draft 4) is a comprehensive method for determining PFAS in various environmental water matrices, including surface water, groundwater, and sediment pore water. The method also provides for the analysis of solid and tissue samples. This method uses the same type of SPE extraction and analysis as Method 533 but adds an additional carbon clean-up step.
8 Key Features of the LCTech FREESTYLE™ XANA™ PFAS System
PFAS Workflow for Liquid Samples with LCTech’s FREESTYLE™ XANA™ PFAS System
The LCTech FREESTYLE™ XANA™ PFAS system is a powerful and efficient solution for laboratories that determine PFAS according to EPA Methods 533, 537.1, and 1633. Its key features make it an ideal choice for this critical work:
Uninterrupted Operation: System reliability and uninterrupted operation feature allow unattended overnight operation of 24-30 samples. No user intervention is required for all steps, including bottle rinsing, sample overpressure, and system rinsing/clean-up.
Method Reproducibility: The system maintains constant sample flow control up to 4 bars, ensuring method reproducibility.
PFAS-free Sample Flow Path: The sample flow path is fluoropolymer-free, and flow is provided using floating piston pumps with a small contact surface area, providing minimal carry-over and fast, easy cleaning.
Easy Loading: Sample vessels (typically 250 mL to 1 L) are extremely easy to load and have a fully automated rinsing feature.
Complete Flexibility: Advanced software with a graphical user interface provides complete flexibility for all method parameters, making method optimization fast and simple. It provides report printout and unlimited method storage.
Compatibility: Any brand of SPE cartridge can be used to perform EPA methods 533, 537.1, and 1633 or DIN 38407-42. LCTech EluClean® SPE columns have been shown to provide the best results obtainable for PFAS determination using these methods.
Safe System: A completely closed system does not require a fume hood.
Easy Sample Transfer: Processed samples are easily transferred to an evaporation system [GERSTEL provides a fast and efficient system (D-EVA) for this].
Demonstrating Accurate Data for EPA Methods
The following figures are key figures of merit obtained on the XANA system using conditions listed in EPA methods 537.1 and 1633.
Results of Initial Demonstration of Accuracy (IDA) for EPA method 537.1
Results of Initial Demonstration of Accuracy (IDA) for EPA method 1633 (draft method)
Conclusion:
In the ongoing battle against PFAS contamination, accurate and efficient analysis methods are paramount. EPA Methods 533, 537.1, and 1633 are essential tools for assessing PFAS levels in drinking water, wastewater, and environmental samples. The LCTech FREESTYLE™ XANA™ PFAS system, with its automation and precision, has proven to be a valuable asset in conducting these analyses effectively and confidently. By combining cutting-edge technology with rigorous regulatory methods, laboratories equipped with the XANA system contribute significantly to safeguarding our environment and public health from the persistent threat of PFAS contamination.
Links: Follow the links below to learn more about PFAS in water.
AppBrief 15 on EPA Method 537.1