Unwanted Ingredients—Highly Specific and Sensitive Method for the Extraction and Quantification of PFAS in Everyday Foods

Abstract

Perfluorinated alkyl substances (PFAS) are anthropogenic substances and can only come from polluted sources. There are many classes of PFAS which can be transformed to perfluoalkyl carboxylic acids and perfluoroalkyl sulfonic acids in the environment. Once they are in this form, they are environmentally mobile and extremely stable with half-lives of decades. These compounds are not innocuous and are implicated in causing many different diseases. In this publication, a method for the extraction and quantitation of perflurocarboxylic acids and perfluorosulfonic acids, using high-resolution liquid chromatography mass spectrometry (HRMS), is evaluated. A QuEChERS extraction method was performed on tomatoes, strawberries and milk purchased from different supermarkets on different days. Recoveries from milk and tomatoes were between 80 and 120%. Matrix effects were significant for strawberries and tomatoes and stable isotope internal standards were required to compensate. PFBA was found in all 3 food types. The total PFAS was 0.68 ng g−1 in milk, 0.20 ng g−1 in strawberries and 0.36 ng g−1 in tomatoes. This study demonstrates the importance of using a robust analytical method to investigate the PFAS content of complex food matrices and in particular the contribution of short-chain PFAS to overall dietary consumption.