A simple and sensitive QuEChERS-based LC-MS/MS method for quantifying 30 per- and polyfluoroalkyl substances (PFAS) in human serum: application to firefighter biomonitoring.

Occupational exposure to per- and polyfluoroalkyl substances (PFAS) is under scrutiny as a potential cancer risk for firefighters. Existing methods for PFAS biomonitoring involve solid-phase extraction (SPE), either conventional or online, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). SPE requires a significant investment of time and technical skill for optimizing many variables to achieve maximum accuracy and precision. This increases analytical costs, making routine PFAS biomonitoring cost-prohibitive for a majority of fire service members. The motivation for this study was to develop an analytical method for measuring 30 PFAS in firefighters' serum (N = 84) using a QuEChERS (quick, easy, cheap, effective, rugged, and safe) protocol. For all target analytes, process efficiency (PE) and recovery efficiency (RE) were between 89 and 126% at 1 μg L-1 and between 85 and 133% at 25 μg L-1 (%RSD ≤ 13) (N = 5). At 1 and 25 μg L-1, matrix effects (ME) for all target PFAS ranged from 78 to 110% and 87 to 117%, respectively (%RSD ≤ 11). Precision criteria were met for all target analytes in both intra-day and inter-day precision assessments (%RSD ≤ 19). Limits of detection (LOD) and quantitation (LOQ) ranged from 0.006 to 0.3 μg L-1 and 0.02 to 0.9 μg L-1, respectively. This high-performance, high-throughput, and cost-effective alternative to the current gold standard for PFAS measurement in serum advances current firefighter biomonitoring capabilities by decreasing the time and cost of analysis, reducing constraints imposed by specialized laboratory equipment and expertise, and optimizing analytical batch processing and workflow.