Non-targeted analysis (NTA) and suspect screening analysis (SSA): a review of examining the chemical exposome

Abstract

Non-targeted analysis (NTA) and suspect screening analysis (SSA) are powerful techniques that rely on high-resolution mass spectrometry (HRMS) and computational tools to detect and identify unknown or suspected chemicals in the exposome. Fully understanding the chemical exposome requires characterization of both environmental media and human specimens. As such, we conducted a review to examine the use of different NTA and SSA methods in various exposure media and human samples, including the results and chemicals detected. The literature review was conducted by searching literature databases, such as PubMed and Web of Science, for keywords, such as “non-targeted analysis”, “suspect screening analysis” and the exposure media. Sources of human exposure to environmental chemicals discussed in this review include water, air, soil/sediment, dust, and food and consumer products. The use of NTA for exposure discovery in human biospecimen is also reviewed. The chemical space that has been captured using NTA varies by media analyzed and analytical platform. In each media the chemicals that were frequently detected using NTA were: per- and polyfluoroalkyl substances (PFAS) and pharmaceuticals in water, pesticides and polyaromatic hydrocarbons (PAHs) in soil and sediment, volatile and semi-volatile organic compounds in air, flame retardants in dust, plasticizers in consumer products, and plasticizers, pesticides, and halogenated compounds in human samples. Some studies reviewed herein used both liquid chromatography (LC) and gas chromatography (GC) HRMS to increase the detected chemical space (16%); however, the majority (51%) only used LC-HRMS and fewer used GC-HRMS (32%). Finally, we identify knowledge and technology gaps that must be overcome to fully assess potential chemical exposures using NTA. Understanding the chemical space is essential to identifying and prioritizing gaps in our understanding of exposure sources and prior exposures. Impact statement This review examines the results and chemicals detected by analyzing exposure media and human samples using high-resolution mass spectrometry based non-targeted analysis (NTA) and suspect screening analysis (SSA).

De facto Water Reuse: Investigating the Fate and Transport of Chemicals of Emerging Concern from Wastewater Discharge through Drinking Water Treatment Using Non-targeted Analysis and Suspect Screening

“…Most previously published studies have applied targeted analysis to quantify specific chemicals in environmental waters. ,,,,− NTA is a more comprehensive tool that is used to capture a wider range of chemical contaminants and allows for a different experimental design compared to targeted chemistry. , Typically, when investigating the fate of CECs in drinking water, a predetermined list of chemicals is selected based on production data, reported environmental presence in surface water or wastewater, and/or possible emerging risks. Targeted measurements are then made in treated drinking water, commonly resulting in many low-level concentrations or nondetected chemicals.…”

Longitudinal Mapping of Personal Biotic and Abiotic Exposomes and Transcriptome in Underwater Confined Space Using Wearable Passive Samplers

“…In chemical exposomic studies, complementary separation and ionization approaches can expand the detectable chemical space. 21 Although GC-MS has been commonly used to analyze silicon exposure samples, many chemicals of emerging concern are detectable only through liquid chromatography− mass spectrometry (LC-MS) platforms. Moreover, capturing the biological exposome is challenging due to the low concentrations of air microorganisms.…”

“…Coupled metagenomic shotgun sequencing and nontargeted high-resolution mass spectrometry (HRMS) can help researchers explore a greater portion of the biological and chemical exposomes. In chemical exposomic studies, complementary separation and ionization approaches can expand the detectable chemical space . Although GC-MS has been commonly used to analyze silicon exposure samples, many chemicals of emerging concern are detectable only through liquid chromatography–mass spectrometry (LC-MS) platforms.…”

Associations of a Prenatal Serum Per- and Polyfluoroalkyl Substance Mixture with the Cord Serum Metabolome in the HOME Study

“…Untargeted metabolomics is a discovery-based technique that comprehensively assesses metabolic profiles and pathways . In tandem with statistical tools like metabolome-wide association studies (MWAS) and pathway enrichment analysis, relations between exposures to PFAS and hundreds to thousands of metabolites and their corresponding biological pathways can be investigated. − As such, untargeted metabolomics is being increasingly used to identify metabolites and pathways associated with human exposure or disease …”

“…While numerous statistical methods have been developed to quantify the potential effects of chemical mixtures, few studies have evaluated the impact of PFAS mixtures on the fetal metabolome. − Understanding the impact of PFAS exposures on the fetal metabolome is important because PFAS can cross the placenta, and the fetus may be more sensitive to environmental exposures compared to later life stages . Furthermore, the investigation of chemical mixtures is critical, given that PFAS exposure does not occur in isolation.…”