Quantitation of Per- and Polyfluoroalkyl Substances (PFAS) in Aquaculture Systems

Abstract

Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals that have been used since the 1940s in a wide variety of applications including water-repellant clothing, stain-resistant sprays, food packaging, and aqueous film forming foam (AFFF). Due to their prevalent use in consumer products, and their persistence in the environment, PFAS have leached into the air, soil, and water, leaving almost no ecosystem untouched. PFAS are known to be bioaccumulative and studies have shown potential links between exposure and several negative human health effects. A large focus has been placed on understanding and regulating PFAS exposure. Contaminated food and water are believed to be the main routes of exposure for the general population. It has been hypothesized that fish and seafood are one of the main dietary sources of exposure, as associations between consumption and PFAS serum concentrations have been observed globally. With efforts to improve environmental conservation and sustainability while keeping up with increasing demands for fish and seafood, aquaculture has grown rapidly since the 1980s. While numerous studies have shown the presence of PFAS in various environments, data regarding the compounds in aquaculture environments is scarce. In recent years, a large focus has been to reduce the potential for environmental interactions with coastal aquaculture facilities, leading to the increase in land-based marine and freshwater systems. There is currently a lack of understanding with regards to the presence of PFAS in aquaculture environments. As farmed fish continues to account for a large portion of fish for consumption, it is important to understand the fate and transport of PFAS in these environments, requiring proper analytical techniques to be developed. A liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the separation and detection of 40 target PFAS. Various solid phase extraction (SPE) cartridges were selected and tested to determine the best extraction technique for the target analytes. Automated and manual SPE setups were compared, and the automated setup shows a statistically significant increase in average recovery and reproducibility. Instrument and method figures of merit show the sensitivity, reproducibility, and robustness of the developed method. The method was applied to a proof-of-concept study testing various types of aquaculture tanks across two facilities and PFAS were found in each of the samples tested.