LC-HRMS screening of per- and polyfluorinated alkyl substances (PFAS) in impregnated paper samples and contaminated soils

Abstract

High per- and polyfluorinated alkyl substance (PFAS) concentrations have been detected in agricultural soils in Southwest Germany. Discharges of PFAS-contaminated paper sludge and compost are suspected to be the cause of the contamination. Perfluorinated carboxylic acids (PFCAs) have been detected also in groundwater, drinking water, and plants in this area. Recently, previously unknown compounds have been identified by high-resolution mass spectrometry (HRMS). Major contaminants were polyfluorinated dialkylated phosphate esters (diPAPs) and N-ethyl perfluorooctane sulfonamide ethanol–based phosphate diester (diSAmPAP). In this study, HRMS screening for PFAS was applied to 14 soil samples from the contaminated area and 14 impregnated paper samples which were from a similar period than the contamination. The paper samples were characterized by diPAPs (from 4:2/6:2 to 12:2/12:2), fluorotelomer mercapto alkyl phosphates (FTMAPs; 6:2/6:2 to 10:2/10:2), and diSAmPAP. In soil samples, diPAPs and their transformation products (TPs) were the major contaminants, but also FTMAPs, diSAmPAP, and their TPs occurred. The distribution patterns of the carbon chain lengths of the precursor PFAS in soil samples were shown to resemble those in paper samples. This supports the hypothesis that paper sludge is a major source of contamination. The presence of major degradation products like PFCAs, FTSAs, or PFOS and their distribution of carbon chain lengths indicate the activity of biotic or abiotic degradation processes and selective leaching processes from the upper soil horizons. Graphical abstract

Efficient workflow for suspect screening analysis to characterize novel and legacy per- and polyfluoroalkyl substances (PFAS) in biosolids

“…1B ) was diagnostic to the partially fluorinated chain (m/z = 442.9750) and the phosphate group (m/z = 78.9596), suggesting ether cleavage during DDMS 2 . The experimental fragmentation observed was consistent with the MassBank spectral database for 6:2 diPAP collected on an LC-quadrupole time of flight (QTOF) MS [ 46 ] which supports level 2a detection confidence on the Schymanski scale [ 40 ]. The complexity of the MS observed for diPAPs in the biosolids is likely due to numerous coextracts in sample matrix.…”

Communicating Confidence of Per- and Polyfluoroalkyl Substance Identification via High-Resolution Mass Spectrometry

“…Consequently, confident identification of a single homologue can provide evidence to support the identification of other homologues in the series. However, studies have varied in their interpretations of the certainty provided by homologue detections, ,, suggesting the need for more harmonized communication of confidence.…”

FindPFΔS: Non-Target Screening for PFAS─Comprehensive Data Mining for MS2 Fragment Mass Differences

“…The specifications and origins of chemicals are shown in the Supporting Information (Table S1 S1] was prepared in MeOH for optimization of the ddMS 2 -method and the validation of FindPFΔS. Two raw paper samples (P1 and P2, provided by the Fraunhofer Institute, for details see 40 ) and two agricultural soil samples (S1 contaminated with PFAS, S2 without known contamination, but background input) were used to test and verify the performance of FindPFΔS in real sample matrix (sample preparation details in Supporting Information, Section S2).…”