USA: two new PFAS drinking water methods on the way
The agency announces method 534 — direct injection for nine compounds — and method 563 for ultra-short-chain PFAS, expected to be finalised in 2026.
- Ultra-short-chain PFAS escape the existing methods because they retain poorly on standard columns — hence a separate method.
- Direct injection shortens sample preparation but demands different background and system cleanliness control from the laboratory.
- Laboratories in the United States mostly work with methods 533 and 537.1 today; the new ones extend the analyte list rather than replace them.
Source: US EPA — new method for testing PFAS in drinking water