We developed next-generation HPLC-MS/MS methods for PFAS analysis in complex wastewater and sludge samples which broaden the range of PFAS compounds improve accuracy, streamline and improve workflow for faster turnaround time. Our methods employ mixed-mode HPLC columns, which enable large volume injection (LVI) of both water samples and biosolid extracts. In some cases, the techniques eliminate the need for solid phase extraction (SPE) for concentration, making it particularly advantageous for PFAS species that are challenging to analyze using SPE.

We are using this new method for analysis of ultrashort PFAS, such as methyl, ethyl, and propyl perfluorinated carboxylates and sulfonates, and trifluoroacetic acid (TFA). These PFAS are typically poorly retained during SPE and usually omitted from conventional PFAS methods. These compounds can be directly injected in 100% aqueous solutions, yielding chromatographically focused peaks with favorable symmetry.
‍
Another useful application targets polyfluoroalkyl phosphates (PAPs), commonly found in sludge and biosolids from wastewater treatment plants (WWTPs) but rarely measured. Although PAPs are compatible with SPE, efficient quantification often necessitates larger volumes of eluting solvent.

Finally, the Total Oxidizable Precursor (TOP) assay is frequently utilized in attempts to close the PFAS mass balance in WW and biosolid extracts. This assay is labor-intensive and costly, and achieving adequate replication for statistical robustness is often impractical due to the large sample volumes required. Additionally, we observed suboptimal recoveries during the final sample concentration step. To address these limitations, we implemented LVI methods that reduce required sample volume and eliminate the need for sample concentration. By minimizing sample volume and eliminating the SPE step, our approach facilitates replicate analyses, thereby enabling more precise determinations of PFAS composition and oxidative efficiency.
‍
Contact us  to Learn More