Recent applications of mass spectrometry in the analysis of transformation products of emerging contaminants in PM_2.5

Abstract

Ambient pollution correlated to fine particulate matter (PM2.5) is a worldwide environmental issue as it is highly associated with human health and eco‐environmental safety. A significant part regarding the toxicity of PM2.5 is attributed to its bonded contaminants. Appreciable efforts have been performed to study the occurrence, exposure, and toxicological properties of chemicals of emerging concerns in PM2.5. Recent works indicated a broad environmental transformation of emerging contaminants in the atmospheric environment and highlighted the significance of PM2.5 bonded transformation products, which may exhibit higher environmental concentrations and toxicities compared to their parent compounds. Among these studies, mass spectrometry has been widely applied for the analysis of transformation products of emerging contaminants in PM2.5 on the aspects of suspect/non‐target screening, structure elucidation, concentration profiling, and toxicity determination. This review describes key mass spectrometry‐based analytical strategies and applications for determining transformation products in PM2.5 and presents outlooks for their analysis.

Fragmentation Pattern-Based Screening Strategy Combining Diagnostic Ion and Neutral Loss Uncovered Novel para-Phenylenediamine Quinone Contaminants in the Environment

“…As PPD-quinones are undocumented transformation products (TPs) that are derived from the natural oxidation of PPDs, targeted identification with commercial standards is inaccessible. Nontargeted identification using high-resolution mass spectrometry (HRMS) enables the recognition of novel compounds without standards and is thus considered as a powerful tool for identifying novel environmental contaminants hitherto unattainable. , It possesses the capability to analyze complex samples, providing high-confidence identification of thousands of specific molecular components from a single analysis. , By coupling MS with separation means including gas/liquid chromatography (GC/LC) system, , applying nontargeted MS acquisitions such as full scan, data-dependent acquisition, and data-independent acquisition, , and leveraging multiple screening strategies based on the fragment and/or isotopic pattern, , a great range of emerging contaminants, accompanied by their congeners have been identified. − Recently, appreciable efforts have been made to leverage HRMS for screening PPD-quinones in various environments. Tian et al first isolated 6PPD-Q in tire wear particle leachate using multidimensional chromatography, inferred its parent compound, and accordingly confirmed its structure using GC/UPLC-HRMS and nuclear magnetic resonance (NMR) analyses .…”

“… 23 , 24 It possesses the capability to analyze complex samples, providing high-confidence identification of thousands of specific molecular components from a single analysis. 25 , 26 By coupling MS with separation means including gas/liquid chromatography (GC/LC) system, 1 , 23 applying nontargeted MS acquisitions such as full scan, data-dependent acquisition, and data-independent acquisition, 27 , 28 and leveraging multiple screening strategies based on the fragment and/or isotopic pattern, 29 , 30 a great range of emerging contaminants, accompanied by their congeners have been identified. 31 − 33 Recently, appreciable efforts have been made to leverage HRMS for screening PPD-quinones in various environments.…”