The method validation study results demonstrate a robust analytical method for the determination of Per- and Polyfluoronated Alkyl Substances. The method was optimized to include all 20 PFAS compounds included in the 2020 EU Drinking Water Directive. A low level for each individual PFAS at 1 ng/L was achieved to compliment the 0.1 µg/L sum of PFAS limit required in the monitoring of drinking water. Analysis was performed using a Xevo TQ-XS coupled to an ACQUITY UPLC I-Class PLUS modified with an isolator column and PFAS kit components and separated using an ACQUITY Premier BEH Shield RP18 Column for accurate and reliable results. The use of ACQUITY Premier Column technology and the unique UniSpray ion source enabled achievement of these low concentration levels with a direct injection method without the need for additional clean up or concentration steps.
The trueness and precision of this LC-MS/MS method determined at three matrix QC levels with seven replicate injections was found to be acceptable for all compounds regardless of chain length. Retention time stability and robustness was proven over the course of the study with RSDs for all compounds under 3.2% across all method performance batches. With an LOQ of 1 ng/mL, this method significantly exceeds requirements in the EU Drinking Water Directive 2020/2184.