Per- and polyfluoroalkyl substances (PFAS) are a large group of man-made chemicals that have been used in a wide range of industrial applications and consumer products since the 1940s. Known for their persistence in the environment and human body - hence the nickname 'forever chemicals' PFAS pose significant concerns for public health and environmental safety.
PFAS comprise a diverse class of thousands of chemicals characterized by the fully (per) or partly (poly) fluorinated carbon chain connected to different functional groups. The carbon-fluorine bond is one of the strongest in organic chemistry, contributing to this class of chemical's remarkable stability. This stability whilst advantageous for applications requiring resistance to heat, water, and oil has made them difficult to control in the environment.
PFAS are found in soil, air, water, and in the blood of humans and wildlife globally. Health studies have linked PFAS exposure to various adverse outcomes, including thyroid disease, elevated cholesterol levels, weakened immune response, and an increased risk of some cancers. Given their persistence, once PFAS enter the environment, they are difficult to remove.
Analysing for PFAS is challenging due to their stability and diversity. In this respect LC‑MS has become the technique of choice for their detection and quantification since it provides the extreme sensitivity required to detect these compounds down to parts per trillion (ppt) levels in complex matrices like waters, foods, and soils.
In response to environmental concerns regulatory authorities have already established methods using LC‑MS to measure defined sets of PFAS compounds, typically 18 to 40, though it is inevitable that more will come in the future.
- EU Regulation 2023/915: Sets maximum levels for 4 specified PFAS (PFOS, PFOA, PFNA, PFHxS) in a number of food products.
- USA EPA 533 and 537.1: PFAS contaminants in drinking water.
- USA EPA 1633: Broader method covering 40 PFAS across a variety of environmental matrices.
We at ROMIL have responded to the challenge presented by PFAS analysis by adapting a number of our established ultra purity solvents for LC‑MS to the requirements of analytical chemists working in this new field. Known as 'ultra pfas' these solvents and reagents undergo a rigorous use test to ensure an ultra low background at sub‑ppt levels of more than 40 PFAS analytes.