First Discovery of Iodinated Polyfluoroalkyl Acids by Nontarget Mass-Spectrometric Analysis and Iodine-Specific Screening Algorithm

Abstract

Per-and polyfluoroalkyl acids (PFAAs) including polyfluoroalkyl carboxylic acids and polyfluoroalkyl sulfonic acids are a large category of crucial environmental pollutants of global concern. Besides known PFAAs, numerous unknown species may exist in the environment, urgently needing discovery and characterization. This study implemented nontarget analysis for a group of novel PFAA pollutants, viz., iodinated PFAAs (I-PFAAs) in wastewater from a fluorochemical manufacturing park by liquid chromatography−high-resolution mass spectrometry in combination with an iodine-specific data-processing algorithm. The algorithm took into account the diagnostic fragment iodine ion (I − ) together with carbon and sulfur isotopologue distributions. In total, 18 I-PFAA formulas involving 21 congeners were identified. Semiquantification was conducted, and the total concentrations of I-PFAAs were 1.9−274.7 μg/L, indicating severe pollution of I-PFAAs in the wastewater. The determined concentrations along with predicted environmental behaviors and toxicities demonstrate that I-PFAAs merit further in-depth investigation. The analytical method including the instrumental analysis and data-processing algorithm can be extended to screening and identification of I-PFAAs in other matrices. Furthermore, the analysis results for the first time provide recognition on the occurrence, distribution features, and pollution status of I-PFAAs in the environment.

Nontarget Analysis and Comprehensive Characterization of Iodinated Polyfluoroalkyl Acids in Wastewater and River Water by LC-HRMS with Cascade Precursor-Ion Exclusions and Algorithmic Approach

“…The relatively high concentrations together with the calculated ecotoxicities and environmental behaviors demonstrate the high significance of IPFAAs for further investigation. IPFAAs may be unintentional byproducts in production of PFASs, as telechelic fluorinated diiodides, PFIs, and FTIs are reactants commonly used in telomerization processes for industrial synthesis of PFASs. , IPFAAs may also be hydrolysis products of iodinated alkyl acyl fluorides and alkyl sulfonyl fluorides, which are intermediates in synthesis of PFASs. , In addition, the presence of IPFAAs may be in connection with iodine transfer polymerization/copolymerization of vinylidene fluoride in synthesis of polyvinylidene fluoride (a very important fluoropolymer) and copolymers, in which iodofluoroalkanes are often used as chain transfer agents and polyvinylidene fluoride products (oligomers) with an iodo end are generated. , The cascade PIE strategy and data-screening algorithm can be expanded to nontarget identification for other pollutants besides IPFAAs, provided that they can generate diagnostic fragment ions in DDA mode. The nontarget identification and comprehensive characterization outcomes present new insights into the occurrence of IPFAAs in the water environment.…”

“…Despite increasing research attention on iodinated PFASs, almost all previously reported iodinated PFASs were nonionizable or neutral compounds, such as PFIs and FTIs. In contrast, ionizable iodinated PFASs, including iodine-containing polyfluoroalkyl carboxylic acids (IPFCAs) and iodine-containing polyfluoroalkyl sulfonic acids (IPFSAs), are still rarely reported. , In a recent study on nontarget screening and analysis of PFASs, we unexpectedly discovered some iodine-containing polyfluoroalkyl acids (IPFAAs), including both IPFCAs and IPFSAs, in fluorochemical industry wastewater with relatively high concentrations. , However, the previous nontarget analysis method was unable to detect IPFAAs in samples as complete as possible, and some IPFAAs might be missed, particularly low-abundance species. Therefore, more sophisticated analytical approaches, such as PIE and cascade PIEs, are needed for the comprehensive characterization of IPFAAs in environmental matrices.…”

“…IPFAAs may be unintentional byproducts in production of PFASs, as telechelic fluorinated diiodides, PFIs, and FTIs are reactants commonly used in telomerization processes for industrial synthesis of PFASs. 55,63 IPFAAs may also be hydrolysis products of iodinated alkyl acyl fluorides and alkyl sulfonyl fluorides, which are intermediates in synthesis of PFASs. 65,66 In addition, the presence of IPFAAs may be in connection with iodine transfer polymerization/copolymerization of vinylidene fluoride in synthesis of polyvinylidene fluoride (a very important fluoropolymer) and copolymers, in which iodofluoroalkanes are often used as chain transfer agents and polyvinylidene fluoride products (oligomers) with an iodo end are generated.…”

Nontarget and Comprehensive Analyses of Halogenated Organic Additives in Electrical Product Plastics by GC-NCI-Q-Orbitrap-HRMS and Cl/Br-Screening Algorithms

“…By virtue of the recently developed cutting-edge chromatographic and mass spectrometric techniques, nontarget analysis methods have been rapidly developed and applied to screening and identification of environmental pollutants, e.g., identification of HOPs in environmental matrices . In environmental studies concerning nontarget analysis, the applied chromatographic and mass spectrometric techniques mainly involve gas chromatography–quadrupole–time-of-flight mass spectrometry, liquid chromatography–quadrupole–time-of-flight mass spectrometry, gas chromatography–quadrupole–Orbitrap–high-resolution mass spectrometry (GC-Q-Orbitrap-HRMS), and liquid chromatography–quadrupole–Orbitrap–high-resolution mass spectrometry (LC-Q-Orbitrap-HRMS) . By means of these GC/LC-HRMS techniques, numerous halogenated organic compounds have been screened and identified, e.g., halogenated polycyclic aromatic hydrocarbons (H-PAHs), halogenated disinfection byproducts, and mix-chlorinated/brominated organic compounds (OClBrs) .…”

“…32 In environmental studies concerning nontarget analysis, the applied chromatographic and mass spectrometric techniques mainly involve gas chromatography−quadrupole− time-of-flight mass spectrometry, 33 liquid chromatography− quadrupole−time-of-flight mass spectrometry, 34 gas chromatography−quadrupole−Orbitrap−high-resolution mass spectrometry (GC-Q-Orbitrap-HRMS), 35 and liquid chromatography−quadrupole−Orbitrap−high-resolution mass spectrometry (LC-Q-Orbitrap-HRMS). 36 By means of these GC/LC-HRMS techniques, numerous halogenated organic compounds have been screened and identified, e.g., halogenated polycyclic aromatic hydrocarbons (H-PAHs), 37 halogenated disinfection byproducts, 34 and mix-chlorinated/brominated organic compounds (OClBrs). 32 Furthermore, some pioneer studies have reported the comprehensive characterization of HOPs in environmental media.…”