Target and Nontarget Analysis of Per- and Polyfluoralkyl Substances in Wastewater from Electronics Fabrication Facilities

Abstract

The goals of this study were to improve our understanding of the types of per- and polyfluoroalkyl substances (PFASs) that occur in wastewater from electronics fabrication facilities (fabs) and to assess the relative concentrations of PFAS species. We collected wastewater samples from three fabs in the United States, analyzed the samples by means of high-resolution mass spectrometry, and implemented complementary target and nontarget analyses. Twelve of 25 target PFASs were quantified in at least one sample, and five perfluorocarboxylates and perfluorobutane sulfonate (PFBS) were quantified in all samples. PFBS was quantified at the highest concentration among the samples (8040 ng L–1) and we expect that its presence is related to the use of photoacid generators during photolithography. The sum concentrations of the target PFASs in the diluted discharge samples from each fab were 623, 394, and 376 ng L–1. Nontarget analysis revealed the presence of 41 homologous series of PFASs comprising 133 homologues. We proposed structures for 15 homologous series of nontarget PFASs, six of which are reported here for the first time. Using an approach for semiquantification of nontarget PFASs, we estimated that the sum concentrations of target and nontarget PFASs in the diluted discharge samples from each fab were 1490, 78 700, and 2170 ng L–1. Our findings are essential for developing alternative photolithography chemicals or informing the implementation of advanced wastewater treatment technologies at fabs.

Identification of point source dischargers of per‐ and polyfluoroalkyl substances in the United States

“…The number of compounds detectable by standardized analytic methods continues to increase, and it is likely that future methods will include testing for total organic fluorine and nontargeted analysis methods for identifying PFAS compounds. For example, testing downstream from three electronics manufacturing facilities identified over 130 nontargeted PFAS compounds that comprised the majority of total PFAS concentration in the discharge samples (Jacob et al, 2021). Another approach to identifying the source of PFAS in surface water or drinking water is to evaluate the ratio of certain types of PFAS associated with different industries (Zhang et al, 2016).…”

Can determination of extractable organofluorine (EOF) be standardized? First interlaboratory comparisons of EOF and fluorine mass balance in sludge and water matrices

“…For example, unlike the total oxidizable precursors (TOP) assay, 19 which is designed to capture perfluoroalkyl acid precursors, EOF analysis captures all organofluorine substances extracted from a sample. Moreover, compared to compound-specific approaches such as non-target analysis, [20][21][22] the EOF approach is not reliant on individual chemical standards.…”

IDSL.UFA assigns high confidence molecular formula annotations for untargeted LC/HRMS datasets in metabolomics and exposomics

“…Our approach to obtain homologous series with polymeric chain increment from a list of input molecular formulas is different from the prior approaches 41-43-40 in which molecular formulas are enumerated only for a known series or chain increment rule. Therefore, our approach has the flexibility to discover new types of homologous series among a collection of formulas.…”