Measurement of Volatile PFAS in Indoor Air Using TD-GC-MS: a Robust Analytical Method to Increase Understanding of a Less Explored Route of Exposure

Polyfluoroalkyl Substances (PFAS) in the Environment
Oral Presentation

Presented by E. Hachmeister
Prepared by H. Calder1, E. Hachmeister2, L. Miles1
1 - Markes International, 1000B Central Park, Western Avenue, Bridgend, (State/Province), CF31 3RT, United Kingdom
2 - Markes International, Inc, 2355 Gold Meadow Way, Gold River, Sacramento, California, 95670, United States


Contact Information: [email protected]; 01443230935

ABSTRACT

Per- and polyfluoroalkyl substances (PFAS) exposure can occur through a number of pathways and one of the less understood routes is through indoor air. Compared to water and soil the movement of PFAS through air can happen relatively unimpeded. In indoor air the materials and items within buildings can be sources of PFAS and the low air exchange rate in many indoor environments can result significantly higher levels than found in ambient air. This makes PFAS in indoor air a potentially important route of exposure. This has lead the CDC to carry out exposure studies for indoor air and dust.

Short chain replacement PFAS species and neutral precursor compound like fluorotelomer alcohols pose a challenge for LC based techniques which are currently used to monitor for other species in air. In this study we evaluate Thermal desorption coupled to gas chromatography and mass spectrometry (TD-GC-MS) as a technique to monitor for these compounds and for use in non-target screening of PFAS in air.

Thermal desorption coupled to gas chromatography and mass spectrometry (TD-GC-MS) is commonly applied to monitoring of hazardous organic compounds in ambient and indoor air. The technique is well suited to monitoring of both volatile and semi-volatile species, and is non-selective. These properties make TD-GC-MS a perfect technique for use in targeted monitoring of the less understood short chain replacements for legacy PFAS and non-targeted screening to identify novel PFAS within samples.

In this study we will show how TD-GC-MS/MS can offer a robust approach to targeted screening with an average method detection limits of 32 pg/m3 for the 19 target compounds chosen, based on a 500L sample being taken. Preliminary data of indoor air collected from an office environment will be shared to demonstrate how this sampling and analysis technique can be applied in the field.