ASTM D 8628:2025

1.1 This test method covers the analysis of ultrashort chain perfluoroalkyl substances (PFAS) listed in Table 2 , in aqueous samples. Ultrashort chain PFAS are defined as PFAS with a carbon chain length of three or fewer. After spiking with isotopically labeled extracted internal standards (EIS) and cleanup on solid phase extraction (SPE) cartridges, aqueous samples are analyzed by liquid chromatography/mass spectrometry (LC-MS/MS). Final sample concentrations are determined by isotope dilution or surrogate standard quantification using the EIS. 1.2 Samples may be extracted and analyzed for ultrashort chain PFAS only or, where subsample size requirements permit, they may also be extracted for longer chain PFAS at the same time. 1.2.1 Recognizing continual advancements in the sensitivity of instrumentation, advancements in column chromatography, and other processes not recognized here, the reporting limit may be lowered assuming the minimum performance requirements of this test method at the lower concentrations are met. 1.2.2 Depending on data usage, this test method may be modified but limited to modifications that improve performance while still meeting or exceeding the test method quality acceptance criteria. Use Practice E2935 or similar statistical tests to confirm that modifications produce equivalent results on non-interfering samples. In addition, use Guide E2857 or equivalent statistics to revalidate the modified test. 1.2.3 Analyte detections between the method detection limit and the reporting limit are estimated concentrations. The reporting limit is based upon the concentration of the A calibration standard. 1.3 Units- The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

71.040.40