Development and validation of an extraction method for the analysis of perfluoroalkyl substances (PFASs) in environmental and biotic matrices

Although long chained PFASs have been phased-out in several countries, their persistence in the environment and bioaccumulative potential cause the environmental and biotic concentrations to remain high, highlighting the need to further monitor these pollutants. Currently several methods are used for the quantification of perfluoroalkyl substances (PFASs) in biological matrices including different ways to correct for recovery losses, each with its specific pros and contras. With this paper we aim to re-evaluate current methodologies and to create an updated new analytical guideline that is applicable for both abiotic and biotic matrices. The developed LC/MS/MS method was validated and shown to be specific, selective, linear, robust and sensitive. Reliable results could still be obtained 6 days after extraction. The recoveries varied, depending on the matrix, between 1% and 100%, but nevertheless, a high accuracy was obtained even at the lowest recoveries. A reduction of sample mass could significantly increase method recoveries and therefore it is highly recommended to take less matrix. We confirmed that using the ISTD closest in terms of functional group and carbon chain length is a suitable method for the quantification of PFASs that lack a corresponding ISTD. The newly described method was, depending on the matrix, similar in terms of sensitivity and reliability compared to a frequently used method and could be used simultaneously in future monitoring studies. Therefore, we recommend to select the purification method based on the target analytes as well as the sample matrix.The newly described method was similar in terms of sensitivity and reliability compared to a frequently used method and a selection of purification methods should be based on the target analyte and sample matrix.