An Economical Alternative for PFAS Screening: Accurate Mass Screening of PFAS by Single Quadrupole LCMS-2050

Per- and Polyfluoroalkyl Substances (PFAS) in the Environment
Oral Presentation

Prepared by E. Hain1, Y. Wang2, R. Marfil-Vega3, A. Jaffe1, V. Zerda-Pinto1, S. Monti1, L. Wiest1
1 - Shimadzu Scientific Instruments, 7102 Riverwood Drive, Columbia, Maryland, 21046, United States
2 - Cerno Bioscience, 4220 S Maryland Pkwy Ste 200, Las Vegas, Nevada, 89119, United States
3 - Shimadzu Co., 1, Nishinokyo Kuwabara-cho, Nakagyo-ku, Kyoto, 604-8511, Japan


Contact Information: [email protected]; 443-656-9255

ABSTRACT

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous and enduring contaminants that have harmful impacts on the environment and public health. Screening methods are needed by laboratories to identify suitable sample preparation and sensitivity requirements for maintaining desired turn-around times along with laboratories researching PFAS remediation. The ability to screen PFAS using single quadrupole liquid chromatography mass spectrometry (SQ-LCMS) provides a novel and economical alternative for these laboratories. SQ-LCMS is less selective compared to TQ-LCMS; therefore, accurate mass determination through line-shape calibration is a powerful technique for improving compound confirmation. An accurate mass, SQ-LCMS method was developed to facilitate screening environmentally relevant PFAS.
The 40 PFAS targets and 31 internal standards from EPA method 1633A (EPAM1633A) were diluted to match EPAM1633A analysis (i.e., in-vial concentrations ranged from 0.2-1560 ppb depending on the analyte). PFAS were separated by a Nexera HPLC and quantified by a Shimadzu LCMS-2050 with a runtime of 14 minutes. Cerno Bioscience MassWorks was used to improve mass accuracy.
Several analytes had a similar mass-to-charge ratio (m/z); therefore, complete chromatographic separation was needed to identify these compounds and ensure no interferences. For example, NMeFOSAA (C11H6F17NO4S, 569.97 m/z) and 13C7-PFUNA ([13C]7C11HF21O2, 569.98 m/z), were resolved at 7.03 and 7.78, respectively. NMeFOSAA contains a sulfur atom, while 13C7-PFUNA does not; therefore, improved spectral accuracy was also beneficial for resolving and confirming these compounds.
Quality control criteria were within acceptable ranges for all standards and controls. A series of eleven replicate injections were used to determine the instrument detection limit (IDL) for all PFAS in laboratory fortified blanks. The IDLs ranged from 0.023 ppb (PFDS) to 1.46 ppb (5:3 FTCA) in-vial. With a short runtime and reasonably low limits, this instrument setup and method provide an economical solution for PFAS screening and makes PFAS detection accessible to laboratories with a smaller budget.