The Ubiquitous Presence of PFAS in the Environment
21 mar 2022
I have written previously about the environmental issues of the widely used per- and polyfluoroalkyl substances (PFAS). These have led to restrictions and gradual phasing-out of specific analogues, e.g., perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) (1). Currently, PFAS are detected in trace concentrations worldwide in biological and environmental matrices, even at remote and pristine locations (2). Rapid, analytical methods are required which take into account matrix effects, such as those due to protein and phospholipid content of samples, and minimise background PFAS contamination from laboratory materials and analytical instruments during sampling and instrumental analysis.
I have written previously about the environmental issues of the widely used per- and polyfluoroalkyl substances (PFAS). These have led to restrictions and gradual phasing-out of specific analogues, e.g., perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) (1). Currently, PFAS are detected in trace concentrations worldwide biological and environmental matrices, even at remote and pristine locations (2). Rapid, analytical methods are required which take into account matrix effects, such as those due to protein and phospholipid content of samples, and minimise background PFAS contamination from laboratory materials and analytical instruments during sampling and instrumental anlaysis.
Trimmel and co-workers(3) extended the use of the hybrid solid phase extraction (HybridSPE®) technique from liquid biological media, such as plasma and serum, to a tissue matrix. A rapid HybridSPE® protocol designed for ultra-performance liquid chromatography–electrospray ionization tandem mass spectrometry (UPLC–ESI–MS/MS) analysis was developed for the determination of 15 per- and polyfluoroalkyl substances (PFAS) in liver tissue from harbour porpoises (Phocoena phocoena).
Figure 1. Sample preparation workflow.
Liver samples were collected from 20 harbour porpoises by-caught along the Norwegian coast and prepared as shown. The extracts were collected and transferred directly for UPLC®–MS/MS analysis. For the method development and validation, matrix standards were prepared from harbour porpoise liver. The chromatographic separation was carried out using an UPLC system coupled to a triple quadrupole mass analyser with a ZSpray ESI ion source. The LC column was a C18 (30 × 2.1 mm, 1.3 µm) at 30 °C using a gradient elution program with 2 mM ammonium acetate in water (A) and ΜeOH (B) as binary mobile phase with a flow rate of 0.25 mL/min. The gradient elution started at 90% A, held for 0.2 min, decreased to 0% within 2.8 min (minute 3.0), held for 0.5 min (minute 3.5), and reverted to 90% at the minute 3.6, which was held for 0.4 min, for a total run time of 4.0 min. Ultra-pure water from an ELGA LabWater system was used throughout.
The method demonstrated acceptable absolute recoveries (%) ranging from 44.4 to 89.4 %. The inter-day method precision ranged from 2.15 to 15.4%, and the method limits of detection (LODs) ranged from 0.003 to 0.30 ng/g wet weight (w.w.).
The highest detection rates were found for PFOS (perfluorooctane sulfonate) and PFOSA (perfluorooctanesulfonamide) with 100%, followed by PFDA ( perfluoro-n-decanoic acid) and PFUnA (perfluoro-n-undecanoic acid) (with 95%, and PFNA (perfluoro-n-nonanoic acid) with 90%. The median concentrations for the most detected target analytes in the liver were: PFOS (60.1 ng/g w.w.)
Why Choose ELGA LabWater?
This work on the ultra-trace determination of PFAS in dolphin livers is yet another example of the highly successful use of ultra-pure water from an ELGA LabWater stand-alone water purification system for the development of new analytical methods for environmental analysis. ELGA’s proven track record in this area speaks for itself.
References
- EU Comission 2020/784 Commission Delegated Regulation (EU) 2020/784 of 8 April 2020 Amending Annex I to Regulation (EU) 2019/1021 of the European Parliament and of the Council as Regards the Listing of Perfluorooctanoic Acid (PFOA), Its Salts and PFOA-Related Compounds. 2020. Available online: https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32020R0784&from=EN
- Joerss, H.; Xie, Z.; Wagner, C.C.; Von Appen, W.-J.; Sunderland, E.M.; Ebinghaus, R. Transport of Legacy Perfluoroalkyl Substances and the Replacement Compound HFPO-DA through the Atlantic Gateway to the Arctic Ocean-Is the Arctic a Sink or a Source. Environ. Sci. Technol. 2020, 54, 9958–9967.
