Extended Performance Evaluation: Single LC-MS/MS for PFAS & Cyanotoxins in Drinking Water

Drinking Water
Oral Presentation

Prepared by K. Xia, R. Marfil-Vega, E. Wang, T. Matsubara
Shimadzu Scientific Instruments, 7102 Riverwood Dr, Columbia, Maryland, 21046, United States


Contact Information: [email protected]; 410-910-0891

ABSTRACT

Both PFAS and cyanotoxins are drinking and surface water contaminants of concern. Many laboratories seek efficient solutions for analyzing both in response to regulatory demands and emergency situations. EPA Methods 537.1 (PFAS), 544 (microcystins and nodularin), and 545 (cylindrospermopsin and anatoxin-a) all use LC-MS/MS, suggesting that a single system capable of handling all methods could improve laboratory efficiency and reduce costs. This study demonstrates an approach for quantifying PFAS and cyanotoxins using one triple quadrupole mass spectrometer that switches between methods while maintaining accuracy and sensitivity.
Eighteen PFAS (EPA Method 537.1), six microcystins, nodularin (Method 544), cylindrospermopsin, and anatoxin-a (Method 545) were analyzed on a Shimadzu LCMS-8060RX triple quadrupole mass spectrometer. PFAS analysis was completed in 18 minutes with a Shim-pack Velox SP-C18 column. Cyanotoxins were analyzed in 8 minutes using a Shim-pack GIST C18 column for Method 545 and a Velox SP-C18 column for Method 544.
Since PFAS analysis uses negative ionization, an acidic mobile phase for cyanotoxin analysis beforehand could cause ion suppression, reducing accuracy and sensitivity. To validate the single-system approach, a batch of 294 injections, including multiple method-switching rounds, was performed. Method changes were followed by rinsing the system with the corresponding mobile phase for five minutes. The system’s robustness, in running all three methods without compromising sensitivity or introducing interference, was further validated through continuing calibration check injections. The results from this extended evaluation, including linearity of calibration curves and accuracies over time, will be discussed in this presentation.