Automated PFAS analysis with advanced online SPE/LC-MS is a powerful tool in analyzing these biological samples, eliminating protein precipitation and off-line SPE, thus resulting in less usage of organic solvents, faster results, and greater lab efficiencies.

With increased demand for the number of samples to be analyzed and for monitoring more PFAS in humans, a faster and more sensitive method needed to be developed. We used the CDC NHANES method 6304.09 as a starting point and we developed a new method by screening different sorbent materials, C18, WAX and DVB and switching from HPLC to UHPLC. The new method has an expanded list of analytes (12 to 38), a decreased run time (from 30 to ~10 mins/sample), and a smaller injection volume (400 µl to 50 µl).

With this new method, a study, conducted by the California Department of Toxic Substances Control, was to better understand the distribution of PFAS in serum versus plasma. 91 paired samples were collected in California and analyzed using the newly developed online solid-phase extraction (SPE) UHPLC/MS/MS method. Twenty PFAS were detected in both serum and plasma matrices with comparable concentration range and detection frequency. Eleven PFAS with detection frequencies higher than 30% showed the coefficient of determination between serum vs. plasma concentrations ranging from 0.710 to 0.985.  Our results suggest that researchers can use either matrix to assess PFAS exposure within reasonable analytical errors.