High-resolution Mass Spectrometry Research Articles

Grafting of -Electroactive Probe onto the glassy carbon electrode for the Detection of Tetracycline in Milk sample

ABSTRACT This paper presents a new Schiff base molecule of (Z)-N’-(2-hydroxy-5-nitrobenzylidene) nicotinohydrazide (BNH) that has been synthesised and characterised using Fourier transform infrared spectroscopy, Proton and Carbon-13 Nuclear Magnetic Resonance and High-resolution Ionisation Mass Spectroscopy. The study herein describes the novel chemical modification of glassy carbon electrode (GCE) by drop casting method using the synthesised Schiff base molecule to detect tetracycline (TC) antibiotic. Improved sensitivity of the electrode to the analyte results from the electrode modification using functional group present in the Schiff bases. The electrochemical behaviour of a modified electrode on tetracycline using voltammetric techniques were studied and optimised. The modified electrode showed a good selectivity in the presence of some interferences. The calibration curve for TC was achieved in a linear range of 10–60 μmol L−1 under optimised conditions. The detection limit and quantification for TC was found to be 2.1 μmol L−1 and 9 μmol L−1. The obtained results suggested that tetracycline may be measured in milk samples using the BNH modified glassy carbon electrode.

The spatial distribution of components in Moringa oleifera (Lam) seed by matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI)

In this paper, 70 % methanol was used as solvent to extract the principal components from Moringa oleifera (Lam) seed with the ratio (w/v, 1:10) by ultrasonic-assisted extraction. The extract in Lam seed was detected by high resolution mass spectrometry and MS/MS spectra. The result suggests that there are three principal components including malic acid, d-trehalose and 4-(α-L-rhamnopyranosyloxy) benzyl glucosinolate in this extract. Based on this result, the spatial distribution of these components in Lam seed was visually obtained by matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). There is much malic acid in the center of endosperm in Lam kernel and little in the shell of Lam seed. d-trehalose is mainly distributed in the seed coat of Lam seed, and almost no d-trehalose is distributed in the kernel of Lam seed. 4-(α-L-rhamnopyranosyloxy) benzyl glucosinolate is distributed in the seed coat and endosperm of Lam seed. The relative content of this compound in the seed coat of Lam seed is much higher than that in the endosperm. The result further suggests that the different component in Lam seed is distributed in different part. This study can provide some valuable reference for efficient extracting active components from Lam.

The marriage between stable isotope ecology and plant metabolomics - new perspectives for metabolic flux analysis and the interpretation of ecological archives.

Even though they share many thematical overlaps, plant metabolomics and stable isotope ecology have been rather separate fields mainly due to different mass spectrometry demands. New high-resolution bioanalytical mass spectrometers are now not only offering high-throughput metabolite identification but are also suitable for compound- and intramolecular position-specific isotope analysis in the natural isotope abundance range. In plant metabolomics, label-free metabolic pathway and metabolic flux analysis might become possible when applying this new technology. This is because changes in the commitment of substrates to particular metabolic pathways and the activation or deactivation of others alter enzyme-specific isotope effects. This leads to differences in intramolecular and compound-specific isotope compositions. In plant isotope ecology, position-specific isotope analysis in plant archives informed by metabolic pathway analysis could be used to reconstruct and separate environmental impacts on complex metabolic processes. A technology-driven linkage between the two disciplines could allow to extract information on environment-metabolism interaction from plant archives such as tree rings but also within ecosystems. This would contribute to a holistic understanding of how plants react to environmental drivers, thus also providing helpful information on the trajectories of the vegetation under the conditions to come.

Secondary Organic Aerosol from OH-Initiated Oxidation of Mixtures of d-Limonene and β-Myrcene.

The chemical composition and physical properties of secondary organic aerosol (SOA) generated through OH-initiated oxidation of mixtures containing β-myrcene, an acyclic monoterpene, and d-limonene, a cyclic monoterpene, were investigated to assess the extent of the chemical interactions between their oxidation products. The SOA samples were prepared in an environmental smog chamber, and their composition was analyzed offline using ultraperformance liquid chromatography coupled with electrospray ionization high-resolution mass spectrometry (UPLC-ESI-HRMS). Our results suggested that SOA containing β-myrcene showed a higher proportion of oligomeric compounds with low volatility compared to that of SOA from d-limonene. The formula distribution and signal intensities of the mixed SOA could be accurately predicted by a linear combination of the mass spectra of the SOA from individual precursors. Effects of cross-reactions were observed in the distribution of isomeric oxidation products within the mixed SOA, as made evident by chromatographic analysis. On the whole, β-myrcene and d-limonene appear to undergo oxidation by OH largely independently from each other, with only subtle effects from cross-reactions influencing the yields of specific oxidation products.

Discovery of Novel Antioomycete Metabolites from the Marine-Derived Fungus Paraconiothyrium sporulosum.

In our screening program for natural products that are effective in controlling plant diseases, we found that the culture filtrate of Paraconiothyrium sporulosum SFC20160907-M11 effectively suppressed the development of tomato late blight disease caused by Phytophthora infestans. Using a bioassay-guided fractionation of antioomycete activity, 12 active compounds (1-12) were obtained from an ethyl acetate extract of the culture filtrate. Chemical structures of five new compounds 1-5 were determined by the extensive analyses of nuclear magnetic resonance (NMR), high resolution mass spectrometry (HRMS), and circular dichroism (CD) data. Interestingly, mycosporulonol (1) and botrallin (8) completely inhibited the growth of P. infestans at concentrations of 8 and 16 μg/mL, respectively. Furthermore, the spray treatment of 1 and 8 (500 μg/mL) successfully protected tomato seedlings against P. infestans with disease control values of 92%. Taken together, these results suggest that the culture filtrates of P. sporulosum SFC20160907-M11 and their bioactive metabolites can be used as new antioomycete agents for Phytophthora late blight control.

Immunoaffinity Intact-Mass Spectrometry for the Detection of Endogenous Concentrations of the Acetylated Protein Tumor Biomarker Neuron Specific Enolase.

Intact-mass spectrometry has huge potential for clinical application, as it enables both quantitative and qualitative analysis of intact proteins and possibly unlocks additional pathophysiological information via, e.g., detection of specific post-translational modifications (PTMs). Such valuable and clinically useful selectivity is typically lost during conventional bottom-up mass spectrometry. We demonstrate an innovative immunoprecipitation protein enrichment assay coupled to ultrahigh performance liquid chromatography quadrupole time-of-flight high resolution mass spectrometry (UPLC-QToF-HRMS) for the fast and simple identification of the protein tumor marker Neuron Specific Enolase Gamma (NSEγ) at low endogenous concentrations in human serum. Additionally, using the combination of immunoaffinity purification with intact mass spectrometry, the presence of NSEγ in an acetylated form in human serum was detected. This highlights the unique potential of immunoaffinity intact mass spectrometry in clinical diagnostics.

H3trica: Versatile Macrocyclic Chelator for [225Ac]Ac3+ and [155/161Tb]Tb3+ Theranostics.

H3trica is a nonadentate chelating ligand intended for coordinating large radiometal ions, such as those used in nuclear medicine. This chelator, featuring a triaza-18-crown-6 macrocycle with three pendant carboxylic acid functional groups, was synthesized and characterized. Complementary nuclear magnetic resonance (NMR) spectroscopy and high-resolution electrospray-ionization mass spectroscopy (HR-ESI-MS) studies were used to explore the coordination of H3trica with metal ions such as La3+, Y3+ (as a model for Tb3+), and Lu3+ at the bulk scale. Thermodynamic solution studies provided valuable insights, highlighting robust metal complexation of H3trica with La3+, Tb3+, and Lu3+, with the most noteworthy log KML value observed for Tb3+ (log KTbL = 17.08), followed by La3+ (log KLaL = 16.64) and Lu3+ (log KLuL = 16.25). Concentration-dependent radiolabeling studies with [225Ac]Ac3+, [155Tb]Tb3+, and [161Tb]Tb3+ demonstrated rapid complexation (5-30 min) under mild conditions (pH 6-7, 25 °C). Importantly, the radiolabeled complexes exhibited stability during incubation in human serum for one-half-life of the corresponding radiometal. Thus, H3trica emerges as a valuable chelator, demonstrating its potential to coordinate the theranostic couple [225Ac]Ac3+/[155Tb]Tb3+ as well as the powerful terbium quartet ([149/152/155/161Tb]Tb3+) with efficiency and stability.

QC-GN2oMS2: a Graph Neural Net for High Resolution Mass Spectra Prediction.

Predicting the mass spectrum of a molecular ion is often accomplished via three generalized approaches: rules-based methods for bond breaking, deep learning, or quantum chemical (QC) modeling. Rules-based approaches are often limited by the conditions for different chemical subspaces and perform poorly under chemical regimes with few defined rules. QC modeling is theoretically robust but requires significant amounts of computational time to produce a spectrum for a given target. Among deep learning techniques, graph neural networks (GNNs) have performed better than previous work with fingerprint-based neural networks in mass spectra prediction. To explore this technique further, we investigate the effects of including quantum chemically derived information as edge features in the GNN to increase predictive accuracy. The models we investigated include categorical bond order, bond force constants derived from extended tight-binding (xTB) quantum chemistry, and acyclic bond dissociation energies. We evaluated these models against a control GNN with no edge features in the input graphs. Bond dissociation enthalpies yielded the best improvement with a cosine similarity score of 0.462 relative to the baseline model (0.437). In this work we also apply dynamic graph attention which improves performance on benchmark problems and supports the inclusion of edge features. Between implementations, we investigate the nature of the molecular embedding for spectra prediction and discuss the recognition of fragment topographies in distinct chemistries for further development in tandem mass spectrometry prediction.

Fate of Carbamazepine and Its Metabolites in a Soil–Aromatic Plant System

The use of reclaimed wastewater for irrigation could result in the release of pharmaceutically active compounds (PhACs) and their metabolites into the agroecosystem. In this study, we investigated the fate of carbamazepine (CBZ) and its metabolites, with the aim of clarifying their behavior in a soil–plant system in a greenhouse experiment. The research was carried out using irrigation water especially fortified with high doses of CBZ (200 or 600 ppb) in order to evaluate the dynamics of CBZ and its metabolites in the soil and basil organs. The results of the study showed that CBZ is easily absorbed by the aerial part of the basil plant. The soil contained two metabolites of CBZ, namely acridine and carbamazepine-10,11-epoxide, as revealed by high-resolution mass spectrometry analyses. In addition, acridine was found in the aerial parts of basil plants. Furthermore, the greater presence of CBZ and its metabolites in bulk soil indicated a positive role of the basil rhizosphere in the degradation of such compounds or a positive role of the plant in the removal of the contaminant by uptake. Considering the observed morphological parameters and the mean CBZ content in wastewater, significantly lower than that used in the experiment, basil can be considered resistant to the application of irrigation water contaminated with CBZ.

A Quasi Real-Time Evaluation of High-Resolution Mass Spectra of Complex Chlorinated Paraffin Mixtures and Their Transformation Products.

Chlorinated paraffins (CPs) are complex mixtures of polychlorinated n-alkanes with multiple carbon- (C-, nC = 9-30) and chlorine homologues (Cl-, nCl = 3-18). The mass spectrometric analysis of CPs is time-consuming and challenging, especially when interferences between CPs, their transformation products, or from the matrix are numerous. These analytical challenges and the lack of appropriate and accessible data evaluation tools are obstacles to their analysis. CP-Hunter is a web-based, open-access data processing platform for the automatic analysis of mass spectra of CPs and their transformation products. Extracts of two consumer plastic materials and sewage sludge were evaluated with CP-Hunter. C- and Cl-homologue distributions were obtained in quasi-real-time and the posterior calculated fingerprints were in agreement with the ones obtained by traditional methods. However, the data extraction and evaluation time were now reduced from several minutes to seconds. The implemented signal deconvolution method, i.e., to resolve mass spectrometric interferences, provides robust results, even when severe matrix effects are present. CP-Hunter facilitates the untargeted analysis of unknown products and the detection and elimination of false positive signals. Finally, data evaluation with CP-Hunter is performed locally without the transfer of data to external servers. The tool is safe, public, and accessible at https://cphunter.cheminfo.org/.

Zwitterionic Thiolate-Protected Ag22(0/I) and Ag20(I) Clusters: Assembly, Structural Characterization, and Antibacterial Activity.

Zwitterionic thiolate ligands have the potential to introduce novel assembly modes and functions for noble metal clusters. However, their utilization in the synthesis of silver clusters remains understudied, particularly for the clusters containing reductive Ag(0) species. In this article, we report the first synthesis of a mixed-valence silver(0/I) cluster protected by zwitterionic Tab as thiolate ligands (Tab = 4-(trimethylammonio)benzenethiolate), denoted as [Ag22(Tab)24](PF6)20·16CH3OH·6Et2O (Ag22·16CH3OH·6Et2O), alongside an Ag(I) cluster [Ag20(Tab)12(PhCOO)10(MeCN)2(H2O)](PF6)10·11MeCN (Ag20·11MeCN). Ag22 has a distinct hierarchical supratetrahedral structure with a central {Ag6} kernel surrounded by four [Ag4(Tab)6]4+ units. High-resolution electrospray ionization mass spectra demonstrate that Ag22 has two free electrons, indicating a superatomic core. Ag20 has a drum-like [Ag12(Tab)6(PhCOO)6(H2O)]6+ inner core capped by two tetrahedral-like [Ag4(Tab)3(PhCOO)2(MeCN)]2+ units. Ag20 can be transformed into Ag22 after its reaction with NaBH4 in solution. Antibacterial measurements reveal that Ag22 has a significantly lower minimum inhibitory concentration than that of the Ag20 cluster. This work not only extends the stabilization of silver(0/I) clusters to neutral thiol ligands but also offers new materials for the development of novel antibacterial materials.

Synthesis of paeonol hydrazone derivatives and their anti-oomycete, anti-fungal, and nematicidal activities.

The natural product paeonol is a rich and sustainable natural bioresource, and its derivatives have various unique biological efficacy. As is well known, Schiff bases are a class of organic compounds with a wide range of biological activities, including anti-fungal, insecticidal, anti-viral, and nematicidal. To discover biorational natural product-based pesticides, nine intermediates (2-10), 12 sulfonylhydrazones (11a-11c, 12a-12c, 13a-13c, and 14a-14c) and 20 benzylidene hydrazones (18a-18r, 19a, and 20a) were synthesized by structural modification of paeonol, and their structures were characterized by proton nuclear magnetic resonance (1H NMR), carbon-13 (13C) NMR, and high-resolution mass spectrometry (HRMS). The stereochemical configurations of compounds 14a, 18d, and 18r were unambiguously confirmed by single-crystal X-ray diffraction. Furthermore, bioactivities of these compounds as anti-oomycete, anti-fungal, and nematicidal agents against three serious agricultural pests, Phytophthora capsici, Fusarium graminearum, and Heterodera glycines were evaluated. Among all tested compounds: (i) compound 7 exhibited promising anti-oomycete against Phytophthora capsici, with a half maximal effective concentration (EC50) value of 15.81 mg L-1; (ii) compounds 2, 7, 10, and 19a displayed promising anti-fungal against F. graminearum, with EC50 values of 12.22, 14.72, 23.39, and 33.10 mg L-1, respectively; (iii) ten compounds (12a-12c, 14c, 18g-18j, 18m, and 19a) showed significant nematicidal activity against H. glycines, with median lethal concentration (LC50) values all less than 30.00 mg L-1. Especially for compound 18g, its LC50 value is the smallest, at 12.65 mg L-1. The research results indicate that introducing nitro groups at the C5 position of paeonol, or introducing halogens at both C5 and C3 positions, can significantly enhance its biological activity against Phytophthora capsici, F. graminearum, and H. glycines. © 2024 Society of Chemical Industry.

Demethylation C–C coupling reaction facilitated by the repulsive Coulomb force between two cations

Carbon chain elongation (CCE) is normally carried out using either chemical catalysts or bioenzymes. Herein we demonstrate a catalyst-free approach to promote demethylation C–C coupling reactions for advanced CCE constructed with functional groups under ambient conditions. Accelerated by the electric field, two organic cations containing a methyl group (e.g., ketones, acids, and aldehydes) approach each other with such proximity that the energy of the repulsive Coulomb interaction between these two cations exceeds the bond energy of the methyl group. This results in the elimination of a methyl cation and the coupling of the residual carbonyl carbon groups. As confirmed by high-resolution mass spectrometry and isotope-labeling experiments, the C–C coupling reactions (yields up to 76.5%) were commonly observed in the gas phase or liquid phase, for which the mechanism was further studied using molecular dynamics simulations and stationary-point calculations, revealing deep insights and perspectives of chemistry.

High-Throughput Covalent Modifier Screening with Acoustic Ejection Mass Spectrometry.

Interests in covalent drugs have grown in modern drug discovery as they could tackle challenging targets traditionally considered "undruggable". The identification of covalent binders to target proteins typically involves directly measuring protein covalent modifications using high-resolution mass spectrometry. With a continually expanding library of compounds, conventional mass spectrometry platforms such as LC-MS and SPE-MS have become limiting factors for high-throughput screening. Here, we introduce a prototype high-resolution acoustic ejection mass spectrometry (AEMS) system for the rapid screening of a covalent modifier library comprising ∼10,000 compounds against a 50 kDa-sized target protein─Werner syndrome helicase. The screening samples were arranged in a 1536-well format. The sample buffer containing high-concentration salts was directly analyzed without any cleanup steps, minimizing sample preparation efforts and ensuring protein stability. The entire AEMS analysis process could be completed within a mere 17 h. An automated data analysis tool facilitated batch processing of the sample data and quantitation of the formation of various covalent protein-ligand adducts. The screening results displayed a high degree of fidelity, with a Z' factor of 0.8 and a hit rate of 2.3%. The identified hits underwent orthogonal testing in a biochemical activity assay, revealing that 75% were functional antagonists of the target protein. Notably, a comparative analysis with LC-MS showcased the AEMS platform's low risk of false positives or false negatives. This innovative platform has enabled robust high-throughput covalent modifier screening, featuring a 10-fold increase in library size and a 10- to 100-fold increase in throughput when compared with similar reports in the existing literature.

Progress, applications, and challenges in high-throughput effect-directed analysis for toxicity driver identification - is it time for HT-EDA?

The rapid increase in the production and global use of chemicals and their mixtures has raised concerns about their potential impact on human and environmental health. With advances in analytical techniques, in particular, high-resolution mass spectrometry (HRMS), thousands of compounds and transformation products with potential adverse effects can now be detected in environmental samples. However, identifying and prioritizing the toxicity drivers among these compounds remain a significant challenge. Effect-directed analysis (EDA) emerged as an important tool to address this challenge, combining biotesting, sample fractionation, and chemical analysis to unravel toxicity drivers in complex mixtures. Traditional EDA workflows are labor-intensive and time-consuming, hindering large-scale applications. The concept of high-throughput (HT) EDA has recently gained traction as a means of accelerating these workflows. Key features of HT-EDA include the combination of microfractionation and downscaled bioassays, automation of sample preparation and biotesting, and efficient data processing workflows supported by novel computational tools. In addition to microplate-based fractionation, high-performance thin-layer chromatography (HPTLC) offers an interesting alternative to HPLC in HT-EDA. This review provides an updated perspective on the state-of-the-art in HT-EDA, and novel methods/tools that can be incorporated into HT-EDA workflows. It also discusses recent studies on HT-EDA, HT bioassays, and computational prioritization tools, along with considerations regarding HPTLC. By identifying current gaps in HT-EDA and proposing new approaches to overcome them, this review aims to bring HT-EDA a step closer to monitoring applications.

UPLC-LTQ-Orbitrap Study on Rat Urinary Metabolites of 5-Methoxy-Alpha-Methyltryptamine.

5-Methoxy-α-Methyltryptamine (5-MeO-AMT) is a new psychoactive substance which is abused due to its hallucinogenic and euphoric effects. This study aimed to study the metabolic characteristics of 5-MeO-AMT. Five rats were given intraperitoneal injection at a dose of 50 mg/kg of 5-MeO-AMT, and their urine was subsequently collected at different times within 7 days. Ultra-high performance liquid chromatography-- tandem high-resolution mass spectrometry (UPLC-LTQ-Orbitrap) was used to detect the precise molecular weight and fragment ions of 5-MeO-AMT and its possible metabolites in the urine sample extracted with benzene-ethyl acetate. Three metabolites, including OH-5-MeO-AMT, α-Me-5-HT, and N-Acetyl-5-MeO-AMT were identified in rats' urine. The major metabolic pathways involved O-demethylation, hydroxylation of indole ring, and Acetylation on aliphatic amines. The results of this study are an important reference for the identification and screening of toxicants of 5-MeO-AMT.

A stochastic approach for parameter optimization of feature detection algorithms for non-target screening in mass spectrometry.

Feature detection plays a crucial role in non-target screening (NTS), requiring careful selection of algorithm parameters to minimize false positive (FP) features. In this study, a stochastic approach was employed to optimize the parameter settings of feature detection algorithms used in processing high-resolution mass spectrometry data. This approach was demonstrated using four open-source algorithms (OpenMS, SAFD, XCMS, and KPIC2) within the patRoon software platform for processing extracts from drinking water samples spiked with 46 per- and polyfluoroalkyl substances (PFAS). The designed method is based on a stochastic strategy involving random sampling from variable space and the use of Pearson correlation to assess the impact of each parameter on the number of detected suspect analytes. Using our approach, the optimized parameters led to improvement in the algorithm performance by increasing suspect hits in case of SAFD and XCMS, and reducing the total number of detected features (i.e., minimizing FP) for OpenMS. These improvements were further validated on three different drinking water samples as test dataset. The optimized parameters resulted in a lower false discovery rate (FDR%) compared to the default parameters, effectively increasing the detection of true positive features. This work also highlights the necessity of algorithm parameter optimization prior to starting the NTS to reduce the complexity of such datasets.

Discovery of Unprecedented Human Stercobilin Conjugates.

Two unique metabolites (M18 & M19) were detected in feces of human volunteers dosed orally with [14C]inavolisib with a molecular ion of parent plus 304 Da. They were generated in vitro by incubation with fecal homogenates and we have evidence that they are formed chemically and possibly enzymatically. Structural elucidation by high resolution mass spectrometry and NMR spectroscopy showed that the imidazole ring of inavolisib was covalently bound to partial structures derived from stercobilin, an end-product of heme catabolism produced by the gut microbiome. The structural difference between the two metabolites was the position of methyl and ethyl groups on the pyrrolidin-2-one moieties. We propose a mechanism of M18 and M19 generation from inavolisib and stercobilin whereby nucleophilic attack from the imidazole ring of inavolisib occurs to the bridging carbon of a stercobilin molecule. The proposed mechanism was supported by computational calculations of molecular orbitals and transition geometry. Significance Statement We report the characterization of two previously undescribed conjugates of the PI3K inhibitor inavolisib, generated by reaction with stercobilin, an end-product of heme catabolism produced by gut microbiome. These conjugates were confirmed by generating them using in vitro fecal homogenate incubation via non-enzymatic and possibly enzymatic reactions. Given the unique nature of the conjugate, it is plausible that it may have been overlooked with other small molecule drugs in prior studies.

Detection of the GH analog somatrogon in sports drug testing: Immunological approaches and LC-HRMS/MS.

Due to the presumed lipolytic and anabolic properties, the misuse of human growth hormone (hGH) and its synthetic analogs in sports is prohibited both in- and out-of-competition. Within this research project, the detectability of somatrogon, a recombinant fusion glycoprotein of 22 kDa hGH and the C-terminal peptide (CTP) of the human chorionic gonadotropin (hCG) β-subunit, with current WADA-approved doping control assays for hGH and hCG was investigated. For that purpose, cross-reactivity tests and a somatrogon administration study were conducted, and only "Kit 2" of the GH isoform differential immunoassays proved applicable to the detection of somatrogon administration in serum. In urine, the immunoassay specific for total hCG yielded presumptively positive findings for several post-administration samples, which can probably be attributed to the presence of an immunoreactive fragment of the hCG β-subunit. As the detectability of somatrogon with these approaches was found to be limited, a highly specific detection assay (LOD: 10ng/mL) for the drug in serum samples was developed by using affinity purification with GH receptor (GHR)-conjugated magnetic beads, proteolytic digestion, and liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS). Following optimization, the approach was comprehensively characterized, and authentic post-administration serum samples were successfully analyzed as proof-of-concept, indicating a detection window of at least 96 h. Consequently, the presented method can be employed to confirm the presence of somatrogon in serum samples, where only "Kit 2" of the currently used immunoassay kits yielded an abnormally high Rec/Pit ratio.

High-Resolution Mass Spectrometry for Human Exposomics: Expanding Chemical Space Coverage.

In the modern "omics" era, measurement of the human exposome is a critical missing link between genetic drivers and disease outcomes. High-resolution mass spectrometry (HRMS), routinely used in proteomics and metabolomics, has emerged as a leading technology to broadly profile chemical exposure agents and related biomolecules for accurate mass measurement, high sensitivity, rapid data acquisition, and increased resolution of chemical space. Non-targeted approaches are increasingly accessible, supporting a shift from conventional hypothesis-driven, quantitation-centric targeted analyses toward data-driven, hypothesis-generating chemical exposome-wide profiling. However, HRMS-based exposomics encounters unique challenges. New analytical and computational infrastructures are needed to expand the analysis coverage through streamlined, scalable, and harmonized workflows and data pipelines that permit longitudinal chemical exposome tracking, retrospective validation, and multi-omics integration for meaningful health-oriented inferences. In this article, we survey the literature on state-of-the-art HRMS-based technologies, review current analytical workflows and informatic pipelines, and provide an up-to-date reference on exposomic approaches for chemists, toxicologists, epidemiologists, care providers, and stakeholders in health sciences and medicine. We propose efforts to benchmark fit-for-purpose platforms for expanding coverage of chemical space, including gas/liquid chromatography-HRMS (GC-HRMS and LC-HRMS), and discuss opportunities, challenges, and strategies to advance the burgeoning field of the exposome.