Single vs Triple for PFAS Analysis? Yes, a Single Quadrupole Mass Spec Fits in the Toolbox.

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

Presented by R. Marfil-Vega
Prepared by K. Luo, O. Shrestha, M. Davis, L. Wiest, E. Wang, X. Xia
Shimadzu Scientific Instruments, 7102 Riverwood Drive, Columbia, MD, 21046, United States


Contact Information: [email protected]; 410-910-0884

ABSTRACT

Most PFAS applications require the sensitivity and specificity of a triple quadrupole mass spectrometer. However, using a triple quadrupole mass spectrometer requires higher maintenance costs, more laboratory space and highly skilled users. Single quadrupole mass spectrometers can also be used for measuring PFAS. Their small footprint integrates easily into active HPLC systems and can be operated by less experienced users. This work evaluates the use of a compact single quadrupole mass spectrometer (SQ) for PFAS analysis where adherence to regulated methods is not required (e.g., evaluation of novel PFAS treatments, rapid evaluation of remediation efforts where PFAS concentration is above sub-ppb level). Twenty-eight common PFAS were analyzed on an HPLC system coupled with a compact LCMS-2050 SQ with a DUIS ionization source. The method utilized a C18 analytical column (2.1 × 50 mm, 2.7 µm) and a C18 delay column (3 × 50 mm, 5 µm). Water containing 5 mM ammonium acetate and methanol were the mobile phases for the gradient elution. Negative mode scans from m/z 50 – 750 and Selected Ion Monitoring (SIM) were used to analyze the 28 analytes. An 18-minute chromatographic method was developed to separate the targeted PFAS. Each PFAS [M-H]- ion used in SIM was calculated based on the chemical formula. The limits of quantitation (LOQ) for the targeted PFAS in neat standard were in the low ng/mL (ppb) concentration range with 80 – 120% accuracy and %RSD (area) below 12%. The linear range for each PFAS varied between 0.1 – 200 ng/mL with the R2 > 0.99. These results showcase the capability of a compact LCMS system for PFAS quantitation with good LOQs (in the sub-ppb range), without the need for sample preparation, and up to 3 orders of magnitude linear range. In this presentation we will describe the method and performance results.