Meeting the EPA per- and polyfluoroalkyl substances (PFAS) water testing requirements at 4 ppt for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) demands analytical sensitivity that manual sample preparation may not reliably sustain across high-volume environmental matrices. Velaris, the laboratory automation platform uniting Skalar, GERSTEL, TRACE, LCTech, and PromoChrom, has launched a PFAS Water Resource Hub consolidating automated workflows for solid-phase extraction (SPE), extractable organic fluorine (EOF), and adsorbable organic fluorine (AOF) across drinking water, surface water, groundwater, wastewater, and sludge matrices.
Key Insights: Targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis alone cannot flag unknown or emerging PFAS analytes not included in the original compound panel. Labs relying solely on targeted methods risk missing non-target fluorinated compounds, creating compliance gaps when regulations expand to new analytes. Integrating AOF and EOF screening alongside targeted SPE workflows addresses that gap directly.
What Do EPA MCL Compliance Deadlines Mean for Workflow Selection?
The EPA’s National Primary Drinking Water Regulation (NPDWR) established enforceable maximum contaminant levels (MCLs) of 4 ng/L (ppt) for PFOA and PFOS, with 10 ng/L MCLs for perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and hexafluoropropylene oxide dimer acid (HFPO-DA, commonly known as GenX). In May 2026, EPA proposed to rescind the individual MCLs for PFHxS, PFNA, and HFPO-DA and the Hazard Index mixture limit. This proposal is not finalized as of August 2026, and the PFOA and PFOS limits at 4 ng/L are confirmed to be retained. Initial monitoring compliance is required by 2027. For environmental labs managing drinking water or groundwater programs, these timelines define the minimum analytical capability required now, not at implementation.
Automated Solid Phase Extraction (SPE) workflows are the primary pre-concentration technique for EPA Methods 533 and 537.1, both approved for NPDWR compliance monitoring. Procurement leads evaluating PFAS testing automation should verify that any SPE platform demonstrates validated recoveries consistent with these method requirements before committing to a workflow.
Automated SPE Addresses PFAS Enrichment Before Targeted Analysis
Automated SPE concentrates and cleans up PFAS analytes from aqueous matrices prior to LC-MS/MS detection. PromoChrom adds dedicated automated SPE capability to the Velaris portfolio, while LCTech contributes SPE consumables and robotic automation. Together, these platforms are designed to reduce manual pipetting steps, lower cross-contamination risk in multi-client workflows, and improve run-to-run consistency for high-throughput environmental programs.
For programs handling wastewater or sludge matrices, automated SPE also addresses the elevated organic load that can suppress ionization in LC-MS/MS. Labs should verify that the selected SPE sorbent chemistry is validated for the specific matrix before transitioning from manual to automated preparation.
Which PFAS Screening Method Is Right for Your Water Matrix?
Adsorbable organic fluorine (AOF) and extractable organic fluorine (EOF) are sum parameters that report total organically bound fluorine rather than individual PFAS compound concentrations. Both use combustion ion chromatography for fluoride determination following sample preparation.
| Parameter | Sample Prep | Matrix Suitability | Reference Standard | Role in Workflow |
| AOF | Activated carbon adsorption | Drinking water, surface water, groundwater, wastewater | ISO 18127:2026; EPA Method 1621 | First-line screening; detects adsorbable organofluorines |
| EOF | SPE pre-concentration with solvent elution | Aqueous matrices with complex organics; sludge | No finalized ISO/EPA method as of 2026 | Targeted enrichment before combustion; complements AOF |
| SPE + LC-MS/MS | SPE pre-concentration | All drinking water, groundwater, surface water matrices | EPA Methods 533, 537.1, 1633A | Compound-specific quantitation; regulatory compliance monitoring |
ISO 18127:2026 specifies the combustion-IC method for AOF, AOCl, AOBr, and AOI, with a minimum detection threshold of 2 µg/L for AOF. Teams assessing AOF should confirm the instrument limit of quantitation performance against the intended regulatory limit before reporting results.
For labs managing surface water and groundwater PFAS testing programs, the combination of AOF as a first-line screen followed by confirmed LC-MS/MS analysis for positive-screening samples represents the most defensible multi-tiered workflow.
Audit and Optimize Your PFAS Water Testing Workflows
Review your current environmental water testing SOPs against EPA Methods 533, 537.1, and 1633A to identify gaps that automated SPE could address before monitoring deadlines. Confirm that any AOF or EOF platform under evaluation demonstrates validated performance against ISO 18127:2026 for your target matrices. Connect your program with accredited environmental testing laboratories to run validated PFAS water analysis workflows.
The original press release can be found here.
This article was created with the assistance of Generative AI and has undergone editorial review before publishing.