PFAS Investigation

Background

Per- and poly-fluoroalkyl substances (PFAS) is a group of man-made chemicals with a unique structure that consists of hydrophilic head and hydrophobic tail providing water and oil repellent properties. The carbon and fluorine bond in their backbone makes them extremely strong and therefore PFAS are found in objects of everyday lives, such as nonstick cookware, takeout containers, cosmetics, firefighting gear and more. However, their strength gave them a nickname "forever chemicals", because once released into the environment, they never break down and stay forever, polluting the environment affecting our health.

Thousands of PFAS have been manufactured with little understanding on their behavior during breakdown and the breakdown products. As a result, we developed a novel two-step method that is able to breakdown these persistent species and understand the breakdown products and mechanisms. The first step, a scouting step, utilizes evolved gas analysis - mass spectrometry (EGA-MS). Any species evolved are transferred from a pyrolyzer attached to Agilent 7890 GC using a short deactivated EGA tube to 5975 MS that detects the evolved species in real-time. This step provides significant temperatures and ions and predictions on breakdown behavior in a very short time. The second step utilizes thermal desorption - pyrolysis - gas chromatography - mass spectrometry (TD-Py-GC-MS) setup. The same pyrolyzer and GC-MS instruments are utilized, however the EGA tube is swapped for a capillary column. The significant temperatures from EGA-MS step are applied for TD-Py-GC-MS analysis where the column allows to separate and identify any evolved species and confirm the predictions and breakdwon products.