Nontarget analysis and comprehensive characterization of halogenated organic pollutants by GC-Q-Orbitrap-HRMS in association with chromatogram segmentation and Cl/Br-specific screening algorithms

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

“…As shown in Figure a–d, the chromatographic peaks of the theoretical monoisotopic exact mass ( m/z 350.88166), 13 C 1 -substituted mass ( m/z 351.88501), 34 S 1 -substituted mass ( m/z 352.87746), and the in-source fragment ion I – ( m/z 126.90502) of C 4 H 4 OF 4 I-SO 3 – were clearly extracted from the full-scan mass spectrum of Post-RO. The isotopologue distribution was well consistent with the theoretical distribution, with a cosine similarity value (cos θ) of 1.000 (refer to the SI and our previous studies for details of the cosine similarity analysis − ), demonstrating the validity of the identified quasi-molecular ion formula and the high accuracy of the nontarget analysis method. In the extracted full-scan mass spectrum at the retention time of C 4 H 4 OF 4 I-SO 3 – (4.32 min), the quasi-molecular ion ( m/z 350.88171) and the characteristic in-source fragment ion I – ( m/z 126.90485) were clearly observed (Figure e).…”

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

“…So far, nontarget analysis has become a practicable approach to realize comprehensive characterization of chemical components in samples, particularly in environmental analysis, finding and analyzing chemical components or some specific categories of chemical compositions in samples as complete as possible. 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) .…”

“…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) . Furthermore, some pioneer studies have reported the comprehensive characterization of HOPs in environmental media. , However, GC-Q-Orbitrap-HRMS operated in negative chemical ionization (NCI) mode (GC-NCI-Q-Orbitrap-HRMS) has not been applied to nontarget analysis of HOPs yet, although it has been proved to facilitate detection of molecular ions and characteristic fragment ions of HOPs .…”

“…So far, nontarget analysis has become a practicable approach to realize comprehensive characterization of chemical components in samples, particularly in environmental analysis, 31 finding and analyzing chemical components or some specific categories of chemical compositions in samples as complete as possible. 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.…”

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 lack of authentic reference standards for most PFASs makes it a great challenge to identify PFASs, particularly emerging/new species. However, nontarget analysis has been proven to be a feasible and reliable alternative measure to screen and identify pollutants, thus mitigating the predicament caused by lack of authentic reference standards. , Advanced chromatography and high-resolution mass spectrometry technologies, such as liquid chromatography-quadrupole-Orbitrap high-resolution mass spectrometry (LC-Q-Orbitrap-HRMS), − liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS), , gas chromatography-Q-Orbitrap-HRMS, , gas chromatography-quadrupole time-of-flight mass spectrometry, and Fourier transform ion cyclotron resonance mass spectrometry, , have been applied to nontarget analysis of various environmental pollutants. , Many nontarget analysis approaches have been recently developed for screening and identifying PFASs, with more than 1000 PFASs identified in various matrices, including commercial products, ,, environmental media, , and biological samples. , LC-Q-Orbitrap-HRMS , and LC-QTOF-MS , operated in the data acquisition modes of full scan, , data-independent acquisition (DIA), and data-dependent acquisition (DDA) have been applied to nontarget analysis of PFASs. However, a more sophisticated strategy for DDA mode, namely, precursor ion exclusion (PIE), has not been reported to carry out nontarget analysis for PFASs, despite its successful application in identifying various other compounds. − By means of PIE, high-abundance precursor ions are excluded in a next repeated analysis, and therefore, more precursor ions with lower abundances can be triggered in DDA mode, as DDA can commonly generate MS/MS spectra for merely a limited number of precursor ions with the highest abundances (e.g., top five ions).…”