Validating blood microsampling for per- and polyfluoroalkyl substances quantification in whole blood

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Toxicology

Background:

• Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants with widespread human exposure.
• Assessing PFAS body burden typically requires invasive blood collection methods.
• Microsampling offers a simpler, less invasive alternative for collecting blood samples.

Purpose of the Study:

• To evaluate microsampling coupled with dried blood spots (DBS) for comprehensive per- and polyfluoroalkyl substances (PFAS) analysis.
• To compare the efficacy of five common extraction techniques for quantifying PFAS from DBS.
• To establish a minimally invasive method for large-scale human biomonitoring of PFAS.

Main Methods:

• Utilized capillary action microsamplers (Trajan hemaPEN®) for controlled collection of whole blood into DBS.
• Compared five extraction methods: protein precipitation (filtered), acid-base liquid-liquid extraction, trypsin protease digestion, and weak anion exchange (WAX) SPE.
• Analyzed 75 target PFAS using high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS).

Main Results:

• Filtered protein precipitation demonstrated the highest recovery (70-130%) for 72 out of 75 PFAS.
• Method reporting limits (MRLs) were established for perfluorooctane sulfonate (PFOS) at 0.17 ng/L and 0.05-0.34 ng/mL for other PFAS.
• Analysis of human samples detected 16 PFAS, with ΣPFOS being the dominant compound (mean 3.3 ng/mL).

Conclusions:

• Filtered protein precipitation is an effective extraction technique for PFAS from DBS collected via microsampling.
• This minimally invasive microsampling protocol is suitable for extensive PFAS analysis in human blood.
• The developed method can serve as a valuable tool for large-scale human biomonitoring studies.