You are here:
Targeted Method for Quantitating Per- and Poly-fluoroalkyl Substances (PFAS) from Biological Samples Using Ultra-High-Performance Liquid Chromatography (UPLC)-Tandem Mass Spectrometry (MS/MS)
Citation:
Smeltz, M., L. McMillan, M. Strynar, AND B. Wetmore. Targeted Method for Quantitating Per- and Poly-fluoroalkyl Substances (PFAS) from Biological Samples Using Ultra-High-Performance Liquid Chromatography (UPLC)-Tandem Mass Spectrometry (MS/MS). SETAC NA Focus Meeting: Environmental Risk Assessment of PFAS, Durham, NC, August 12 - 15, 2019.
Impact/Purpose:
This poster details a sensitive, quantitative method using ultra-high-performance liquid chromatography (UPLC) combined with triple quadrupole tandem mass spectrometry (MS/MS) to determine PFAS in biological samples. Over 40 PFAS of different classes, including perfluoroalkyl carboxylic acids, perfluoroalkyl sulfonic acids, and more unique PFAS with ether linkages and sulfonamides, have been detected with this UPLC-MS/MS method with quantitation limits in the pg/μL range. This analytical approach continues to be used to assess the quality of PFAS standards and to provide quantitative measures of each PFAS in a range of in vitro experimental toxicokinetic assays.
Description:
A sensitive quantitative method using ultra-high-performance liquid chromatography (UPLC) combined with triple quadrupole tandem mass spectrometry (MS/MS) was developed to determine per- and polyfluoroalkyl substances (PFAS) in biological samples, specifically using human plasma to determine various toxicokinetic (TK) measures. This method was applied to more than 20 PFAS of different classes such as perfluoroalkyl carboxylic acids and perfluoroalkane sulfonic acids, as well as more unique PFAS that contain ether linkages and sulfonamides. Additionally, a dozen 13C- and 2H-labelled PFAS were included as internal standards in this method. Detection limits were in the low to sub-pg/μL range depending on the analyte employing a Waters Xevo TQ-S micro system and an ACQUITY I-Class UPLC with Waters PFC Analysis Kit. All compounds were included within this rapid method (8.5 min total run time) using a mobile phase consisting of water, acetonitrile, and 2.5 mM ammonium acetate. For application, this method evaluated the presence and quality of PFAS standards in DMSO. Assessment through simultaneous MS full scan acquisition and multiple reaction monitoring (MRM) mode, a technique known as RADAR©, allowed for monitoring of impurities and degradants without impacting instrument sensitivity. Our analysis indicated that most carboxylic acid-containing PFAS were of high quality, while some of the sulfonate-bearing compounds presented as a mixture of linear and branched isomers. These findings assisted with our targeted analyses to monitor for TK properties, identifying troublesome compounds that may require additional optimization or sample preparation. Subsequently, plasma protein binding assays by ultracentrifugation and rapid equilibrium dialysis were analyzed with this developed approach. Measured plasma protein binding indicated very high binding rates for most studied PFAS, attesting to the sensitive detection capabilities of this developed UPLC-MS/MS method. Using this method, we plan to continue hazard and exposure evaluation of various TK measures across a broad group of PFAS. The views expressed in this abstract are those of the authors and do not necessarily represent the views or policies of the U.S. Environmental Protection Agency.
