bims-metlip 2026-11-01 papers

bims-metlip

Biomed News

on Methods and protocols in metabolomics and lipidomics

Issue of 2026–11–01
38 papers selected by
Sofia Costa, Matterworks

Highly sensitive determination of polyunsaturated fatty acids by permanently charged derivatization-liquid chromatography-electrospray ionization tandem mass spectrometry.
Quantification of Upadacitinib, Dasatinib, Ruxolitinib, Imatinib, and Cabozantinib in Plasma With Liquid Chromatography-Tandem Mass Spectrometry.
Enhancing untargeted lipidomics using offline two-dimensional LC-MS and systematic evaluation of data processing tools.
A Practical Guide to Dereplication in Natural Products Metabolomics.
[Determination of resorcinol in serum by high-performance liquid chromatography-tandem mass spectrometry].
Development and Validation of an UPLC-QqQ MS/MS Method for the Determination of Daraxonrasib, a New pan-KRAS Inhibitor, in Dog Plasma and Whole Blood and Its Application to Pharmacokinetic Studies.
Expanding the Measurement Space of Ion Mobility-Mass Spectrometry Using Chemical Derivatizations.
Rapid Broad-Polarity Screening of 459 Emerging Contaminants in Environmental Waters by Online Polarity-Partitioned Two-Dimensional Liquid Chromatography-Tandem Mass Spectrometry.
Enhancing Sensitivity of Atmospheric Pressure Laser Ablation Carbon Fiber Ionization Mass Spectrometry Imaging for Endogenous Metabolites Using a Polydopamine/Covalent Organic Framework Composite.
Determination of Bongkrekic Acid and Iso-Bongkrekic Acid in Red Yeast Rice and Its Related Products by Liquid Chromatography-Tandem Mass Spectrometry.
Quantification of clofazimine, linezolid, levofloxacin, and moxifloxacin in breast milk by online solid phase extraction coupled to LC-MS/MS.
Detecting and Quantifying Variability in Mass Spectrometry-Based Metabolomics Datasets.
A High-Resolution Mass Spectrometry Workflow for Xenobiotic Metabolite Discovery and Toxicity Prioritization: Disperse Orange 61 as a Case Study.
Data processing in proteomics and metabolomics: liquid chromatography-mass spectrometry-based omics with divergent computational paradigms.
Measurement of Lipid Oxidation in Foods and Selected Biological Systems Using LC-MS/MS-Based Lipidomics.
Data-Driven Mechanistic Modeling of Untargeted Metabolome Data.
Comprehensive characterization of regulated and emerging marine toxins by UHPLC-IM-QTOF using automated MS/MS and collision cross section measurements.
A Comprehensive GC-MS Toolbox for Targeted and Untargeted Sterol Analysis.
Mass Spectrometry Imaging-Guided Proteomics, an Emerging Frontier in Spatial Biology.
Complementary Orthogonal Approaches for Metabolite Profiling of Chamaelirium luteum (False Unicorn) Root Preparations and Commercial Products.
Liquid chromatography-mass spectrometry approaches for analysis of polychlorinated alkanes: a review.
Comparison of Two Passive Samplers for Hydrophilic and Lipophilic Phycotoxins and Expansion of Analytical Methods for Quantification Using UPLC-MS/MS.
Vanadium Pentoxide-Mediated Oxidation Coupled with HPLC-MS/MS for Broad-Spectrum Screening of Paralytic Shellfish Toxins in Plasma.
Dried Urine Spots for Quantification of C0 (Free) Carnitine Excretion: A Validated Method for Follow-Up and Confirmatory Testing of Primary Carnitine Deficiency.
From LC-MS Metabolomic Profiling to AIEnabled Navigation of NPs Chemical Space: Recent Advances and Emerging Directions.
spatialMET: an open and scalable framework for spatial metabolomics analysis.
Quantification of multi-class pesticides in wipes dust by liquid chromatography - mass spectrometry: development and application in rural households.
Analytical Validation of a Multielement ICP-MS Method for Human Serum and Its Application to Trace Element Biomonitoring in Hemodialysis Patients.
When nucleosides interfere with pyrimidine base quantification. Example of dihydropyrimidine dehydrogenase phenotyping.
Recent Advances in the Enantiomeric Separation of Tropane Alkaloids by Liquid Chromatography: Analytical Strategies and Applications in Pharmaceutical, Biological, and Food Samples.
Rapid ultrasound-assisted enzymatic hydrolysis coupled with LC-MS/MS for sensitive detection of tyrosine adducts in OPNAs-exposed plants.
Mass Spectrometry Imaging for Mapping the Spatial Distribution of Bioactive Compounds in Medicinal Fungi: Applications, Challenges, and Future Perspectives.
Validation of a HILIC-LC-MS/MS Method for Simultaneous Determination of Paralytic Shellfish Toxins and Tetrodotoxins in Multiple Marine Matrices: The Critical Role of Matrix Effects.
Identification of Microplastics by Calcined Sand Assisted Ambient Laser Desorption Electrospray Ionization Mass Spectrometry.
Rapid Screening of Aldehydes by SICRIT-HRMS: Understanding Ionization Behavior in Breath Analysis.
Determination of Pyrrolizidine Alkaloids in Tea and Herbal Infusions by LC-MS/MS.
Spatial Lipidomic Analysis Using Secondary Ion Mass Spectrometry (SIMS).
Natural Antioxidant-Derived Compounds and Materials as Emerging MALDI Matrices: Applications, Evidence, and Perspectives.

Anal Sci. 2026 Oct 27.

Highly sensitive determination of polyunsaturated fatty acids by permanently charged derivatization-liquid chromatography-electrospray ionization tandem mass spectrometry.

Kento Sonogi, Shimba Kawasue, Reiko Koga, Hitoshi Nohta, Hideyuki Yoshida.

  Polyunsaturated fatty acids (PUFAs) are essential dietary components. However, they must be obtained from food because the human body cannot synthesize them in sufficient quantities. Furthermore, PUFA content can vary slightly depending on the type of food and storage conditions, making it necessary to establish accurate and highly sensitive methods for their quantification. However, their sensitive determination remains challenging because of the poor ionization efficiency of conventional liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-MS analyses. In this study, we developed a highly sensitive LC with tandem mass spectrometry (LC-MS/MS) method for PUFA analysis based on permanently charged derivatization using TPP-AEP. This derivatization reagent has a quaternary ammonium structure, which is required for efficient ionization under mild electrospray ionization (ESI)-MS conditions. Consequently, the [M]⁺ ions of PUFAs derivatized with TPP-AEP were detected with high sensitivity. Solid-phase extraction (SPE) was used for sample preparation to remove impurities. Furthermore, a C18 column was used for LC separation with an acidic mobile phase to achieve good peak shapes and stable detection sensitivity in PUFA analysis. The developed method exhibited excellent linearity (r2 ≥ 0.9983) and achieved a low limit of quantification in the range of 2.80-3.29 ng/mL for the examined PUFAs (5,8,11,14,17-eicosapentaenoic acid, 4,7,10,13,16,19-docosahexaenoic acid, arachidonic acid, and linoleic acid). Application of the method to PUFAs extracted from muscle tissues of four marine fish species demonstrated that the combination of lipid extraction, alkaline hydrolysis, derivatization, SPE, and LC-MS/MS allowed for the quantification of both free and total PUFA content with high sensitivity.

Keywords:  Derivatization; Fish muscle tissues; LC–MS/MS; Polyunsaturated fatty acid

DOI:  https://doi.org/10.1007/s44211-026-00980-4
Ther Drug Monit. 2026 Oct 28.

Quantification of Upadacitinib, Dasatinib, Ruxolitinib, Imatinib, and Cabozantinib in Plasma With Liquid Chromatography-Tandem Mass Spectrometry.

Mohsin El Amrani, Pim M A Keur, Kim C M van der Elst, Bognàr Tim.

   BACKGROUND: Tyrosine kinase inhibitors (TKIs) are increasingly used to treat hematological malignancies and solid tumors. As pharmacokinetic variability is substantial among patients, therapeutic drug monitoring may help optimize treatment efficacy and minimize toxicity. However, simultaneous quantification of multiple TKIs with markedly different therapeutic concentration ranges is challenging. A sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for simultaneous quantification of upadacitinib, dasatinib, ruxolitinib, imatinib, and cabozantinib in human plasma.
METHODS: Proteins were precipitated in methanol containing stable isotope-labeled internal standards. Rapid chromatographic separation (5 minutes) was achieved on a BEH C18 column using a gradient of 0.025% ammonium hydroxide in water and methanol. TKIs were detected using a triple-quadrupole mass spectrometry in positive electrospray ionization mode. EMA ICH M10 guidelines were used for method validation.
RESULTS: All analytes showed excellent linearity (R2 ≥ 0.9992) over calibration ranges of 0.1-10,000 mcg/L depending on the analyte. Lower limits of quantification were 0.1 mcg/L for upadacitinib and dasatinib, 0.5 mcg/L for ruxolitinib, 2.25 mcg/L for cabozantinib, and 10 mcg/L for imatinib. Within-run and between-run precision were ≤4.7% and ≤3.1%, respectively, and accuracy ranged from 0.1% to 13.2%. No significant matrix effects, carryover, or interference were observed. All analytes were stable during short-term storage (3 days at 5°C and 20°C), freeze-thaw cycles, and long-term storage (12 months at -20°C and -80°C).
CONCLUSIONS: This simple, rapid, sensitive, and robust LC-MS/MS method enables simultaneous quantification of 5 TKIs at different concentrations with minimal sample volume and excellent analytical performance, supporting its use in therapeutic drug monitoring and pharmacokinetic studies of kinase inhibitors in clinical practice.

Keywords:  LC–MS/MS; oral oncolytic drug; quantification; therapeutic drug monitoring; tyrosine kinase inhibitor

DOI:  https://doi.org/10.1097/FTD.0000000000001535
Anal Chim Acta. 2026 Dec 01. pii: S0003-2670(26)01268-7. [Epub ahead of print]1425 346318

Enhancing untargeted lipidomics using offline two-dimensional LC-MS and systematic evaluation of data processing tools.

Fernanda Sousa Monteiro, Adriana Zardini Buzatto, Liang Li.

  Although two-dimensional liquid chromatography-mass spectrometry (2DLC-MS) has been explored to improve lipidomic coverage, its practical implementation remains limited by challenges in fractionation design and interpretation of complex datasets. Here we report an optimized offline hydrophilic interaction chromatography-reversed-phase liquid chromatography (HILIC-RPLC) 2DLC-MS workflow for untargeted lipidomics. A simplified five-fraction HILIC strategy was developed to enhance lipid class separation while maintaining practical analytical throughput. Optimization of solvent composition, mobile phases, and gradient conditions improved compatibility between chromatographic dimensions and enabled efficient fractionation prior to RPLC-MS analysis. Compared with conventional one-dimensional RPLC-MS, the proposed workflow reduced lipid co-elution and ion suppression, resulting in approximately two-fold higher lipid feature coverage in biological samples including serum, tissue, and cultured cells. Chromatographic fractionation information was further used as an orthogonal parameter to evaluate lipid annotation reliability. Using this framework, three lipidomics software platforms-MetaboScape, MS-DIAL, and LipidScreener-were systematically evaluated for processing 2DLC-MS datasets. The results reveal substantial variability among software tools and demonstrate that integrating chromatographic fractionation with data processing improves confidence in untargeted lipidomic analysis.

Keywords:  Data processing and annotation; Hydrophilic interaction chromatography; Lipidomics; Reversed-phase LC; Two-dimensional LC

DOI:  https://doi.org/10.1016/j.aca.2026.346318
J Nat Prod. 2026 Oct 23. 89(10): 2764-2782

A Practical Guide to Dereplication in Natural Products Metabolomics.

Jiangpeiyun Jin, Neha Garg.

  Liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based metabolomics has become a central approach for characterizing the chemical diversity of biological systems, particularly in natural product discovery. However, the scale and complexity of untargeted LC-MS/MS datasets present a persistent challenge: only a small fraction of detected features can be confidently assigned to known structures, leaving much of the metabolome unexplored. Dereplication and annotation tools have rapidly expanded to address this bottleneck, including molecular networking, spectral library matching, substructure discovery, chemical class prediction, in silico structure prediction, and repository-scale spectral searching. For beginners, these growing computational tools can be difficult to navigate since individual tools differ in input requirements, confidence levels, and optimal use cases. This review provides a practical overview of major annotation strategies in LC-MS/MS-based metabolomics and emphasizes how complementary tools can be integrated into coherent workflows. We first introduce core approaches for feature organization and dereplication, then discuss advanced strategies for substructure analysis, chemical classification, de novo annotation, and genome-informed discovery. Finally, representative applications from studies on different biological systems illustrate how integrative workflows enable prioritization, structural characterization, and discovery of previously unknown chemistry and biochemical reactions.

Keywords:   in silico tools; annotation; computational metabolomics; dark metabolites; mass spectrometry; metabolomics; natural product discovery

DOI:  https://doi.org/10.1021/acs.jnatprod.6c00896
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi. 2026 Oct 20. 44(10): 853-856

[Determination of resorcinol in serum by high-performance liquid chromatography-tandem mass spectrometry].

X H Chen, Y J Zhang, J Zhou.

  Objective: To establish a method for the determination of resorcinol in serum by liquid chromatography tandem mass spectrometry. Methods: In June 2024, the serum samples were extracted with ammoniated acetonitrile, cleaned up by a PRiME MCX solid phase extraction column. Separation was performed on a Waters HSS T3 column (100 mm×2.1 mm, 1.8 μm) with a linear gradient elution program of water and acetonitrile as the mobile phase. The analyte was measured by using electrospray ion (ESI) in the negative multiple reaction monitoring (MRM) mode. Quantification was carried out by the external standard method. Results: A good linearity was obtained in the concentration range of 2.0~100.0 μg/L for target compound with the correlation coefficient greater than 0.999. The limit of detection (LOD) and the limit of quantitation (LOQ) were 0.7 μg/L and 2.0 μg/L.The average spiked recovery was 89.8%, the intra-day precision was 2.8%~5.6%, and the inter-day precision was 4.1%~7.3%. Conclusion: The established method was of high accuracy and sensitivity, and was suitable for the determination of resorcinol in human serum.

Keywords:  Chromatography, high pressure liquid; Resorcinols; Serum; Solid phase extraction; Tandem mass spectrometry

DOI:  https://doi.org/10.3760/cma.j.cn121094-20240913-00430
Biomed Chromatogr. 2026 Dec;pii: e70647. [Epub ahead of print]40(12):

Development and Validation of an UPLC-QqQ MS/MS Method for the Determination of Daraxonrasib, a New pan-KRAS Inhibitor, in Dog Plasma and Whole Blood and Its Application to Pharmacokinetic Studies.

Wentao Zhang, Yanzi Liu, Ali Fan, Xuan Geng.

  Daraxonrasib, an orally administered pan-RAS inhibitor, is undergoing clinical evaluation for pancreatic ductal adenocarcinoma, colorectal cancer, and non-small cell lung cancer. Defining its pharmacokinetic profile is therefore critical for ongoing progress. Accordingly, a simple and sensitive UPLC-QqQ-MS/MS assay was developed and validated to quantify daraxonrasib in canine plasma and whole blood. Proteins were precipitated with a 20:80 (v/v) acetonitrile-methanol solution containing 0.1% formic acid. Chromatographic separation was performed on a Waters ACQUITY BEH C18 column (50 mm × 2.1 mm, 1.7 μm). The mobile phase consisted of 2 mM ammonium acetate and acetonitrile, each containing 0.1% formic acid, delivered at 0.4 mL/min. Multiple reaction monitoring transitions for daraxonrasib and the internal standard were m/z 811.5 → 680.3 and m/z 724.4 → 396.2, respectively. Calibration standards showed linear response from 1.0 to 1000 ng/mL (r > 0.998). The assay met validation criteria for specificity, recovery, limit of quantification, accuracy, and precision. Finally, this validated method was applied to a dog pharmacokinetic study of daraxonrasib. This report outlines the drug's pharmacokinetic characteristics and supports its continued development.

Keywords:  UPLC‐QqQ‐MS/MS; bioavailability; daraxonrasib; pan‐KRAS; pharmacokinetics

DOI:  https://doi.org/10.1002/bmc.70647
ACS Meas Sci Au. 2026 Oct 21. 6(5): 1825-1836

Expanding the Measurement Space of Ion Mobility-Mass Spectrometry Using Chemical Derivatizations.

Sabrina Fernandez, Angela Acateca, Bradley B Garrison, Heidi M Sabatini, Christopher D Chouinard.

  Steroid analysis by mass spectrometry remains challenging because many compounds exhibit both poor ESI efficiency and subtle structural differences that limit differentiation by conventional techniques. While chemical derivatization has historically been employed to improve analytical sensitivity, its broader influence on ion mobility-mass spectrometry (IM-MS) measurements has not been systematically investigated. Here, seven hydrazine-based derivatization reagents were evaluated across a panel of 16 isomeric 11-oxosteroids using IM-MS and matrix-assisted laser desorption/ionization (MALDI)-MS. All derivatization chemistries systematically altered both molecular mass and collision cross section (CCS), producing reagent-specific shifts through CCS vs m/z measurement space. Beyond these global shifts, several reactions generated characteristic mobility fingerprints composed of multiple mobility-resolved structural populations, providing substantially richer structural information than CCS alone. The analytical utility of these measurements was demonstrated through improved differentiation of structurally similar steroid isomers using complementary descriptors including CCS, reaction stoichiometry, mobility fingerprints, and reagent-specific isotopic signatures. Finally, successful translation of the derivatization chemistry to MALDI analysis, including direct surface derivatization, established compatibility with alternative ionization methods and supports future integration with mass spectrometry imaging (MSI) workflows. Collectively, these results demonstrate that chemical derivatization fundamentally expands the analytical information accessible by IM-MS and establishes a general framework for engineering molecular measurements through differential, yet controlled, manipulation of molecular mass, CCS, and gas-phase structural diversity.

Keywords:  derivatization; ion mobility-mass spectrometry; steroids; structures for lossless ion manipulations (SLIM); tandem mass spectrometry

DOI:  https://doi.org/10.1021/acsmeasuresciau.6c00210
J Sep Sci. 2026 Oct;pii: e70561. [Epub ahead of print]49(10):

Rapid Broad-Polarity Screening of 459 Emerging Contaminants in Environmental Waters by Online Polarity-Partitioned Two-Dimensional Liquid Chromatography-Tandem Mass Spectrometry.

Xingyu Shi, Lisong Chen, Qisheng Zhong, Lingling Shen, Hongyuan Hao, Ting Zhou.

  A rapid, broad-polarity targeted screening method based on online polarity-partitioned two-dimensional liquid chromatography-tandem mass spectrometry (2D-LC-MS/MS) was developed for the determination of 459 emerging contaminants (ECs) in environmental waters. The target panel covered nine classes, including herbicides, fungicides, insecticides, pharmaceuticals and personal care products, hormones, plant growth regulators, per- and polyfluoroalkyl substances, flame retardants, and preservatives. In this configuration, highly polar compounds were retained and separated in the hydrophilic interaction chromatography (HILIC) dimension, whereas weakly retained medium- and low-polarity compounds were transferred online, diluted, and further separated in the reversed-phase liquid chromatography (RPLC) dimension. This polarity-partitioned HILIC/RPLC workflow expanded the chemical coverage of targeted EC monitoring and enabled the analysis of target compounds within 28 min. Combined with a lyophilization-based sample preparation procedure, the method was validated in terms of linearity, accuracy, precision, recovery, and matrix effects. The validated method was then applied to tap water and wastewater samples to demonstrate its applicability for broad-spectrum environmental monitoring. Five ECs, mainly including neonicotinoid insecticides and triethyl phosphate, were detected in tap water at concentrations of 0.26-7.65 µg/L, while nine ECs, mainly including sulfonamide antibiotics, pesticides, triethyl phosphate, carbamazepine, and perfluorooctanoic acid, were found in wastewater at 0.37-5.37 µg/L. These results demonstrate that the developed online 2D-LC-MS/MS method provides a rapid and efficient tool for screening ECs with diverse physicochemical properties in environmental waters and supporting high-throughput water quality surveillance.

Keywords:  broad‐polarity screening; emerging contaminants; environmental waters; lyophilization; two‐dimensional LC‐MS/MS

DOI:  https://doi.org/10.1002/jssc.70561
Anal Chem. 2026 Oct 27. 98(42): 29892-29902

Enhancing Sensitivity of Atmospheric Pressure Laser Ablation Carbon Fiber Ionization Mass Spectrometry Imaging for Endogenous Metabolites Using a Polydopamine/Covalent Organic Framework Composite.

Lanlan Wang, Yuting Chen, Yingchao Liu, Xu Chen, Li Zhang, Jing Zhang, Lixing Zhan, Yinlong Guo, Xiaopan Liu.

The spatial distribution of endogenous small-molecule metabolites is pivotal for understanding living processes, disease mechanisms, and therapeutic principles. However, achieving high-sensitivity spatial metabolomic profiling remains challenging for atmospheric pressure mass spectrometry imaging (AP-MSI) due to low desorption/ionization efficiency, leading to the systematic omission of low-abundance yet biologically vital metabolites from spatial maps. Here, we developed a high-sensitivity MSI platform that integrated a polydopamine/covalent organic framework (PDA/COF) composite substrate with atmospheric pressure laser ablation carbon fiber ionization (LACFI) technology for spatial mapping of endogenous small-molecule metabolites in biological tissues. This substrate employed a polydopamine (PDA) interlayer to guide the ordered assembly of a COF on the substrate. The resulting PDA/COF composite substrate exhibited uniform surface coverage, strong stability, and excellent light absorption, collectively improving the laser desorption/ionization efficiency of metabolites. Moreover, the substrate was simple, easy to use, and cost-effective. Our platform demonstrated a significantly enhanced sensitivity, achieving an improvement of more than 2-fold based on the slope of the linear calibration curve for analysis of metabolites compared with MALDI, DESI, LACFI using copper-coated, graphene oxide, and COF substrate. It also exhibited excellent linear response, wide dynamic range, and broad metabolite coverage. The platform was further applied to map the metabolomes of normal, para-cancerous, and cancerous liver tissues and, through heatmap analysis, clearly revealed the spatial distribution patterns of metabolites such as NAD+ and adenine across these tissue types. This method provides a straightforward, efficient, and robust AP-MSI platform for highly sensitive and comprehensive spatial metabolomics.

DOI: https://doi.org/10.1021/acs.analchem.6c05938
Toxins (Basel). 2026 Sep 22. pii: 407. [Epub ahead of print]18(10):

Determination of Bongkrekic Acid and Iso-Bongkrekic Acid in Red Yeast Rice and Its Related Products by Liquid Chromatography-Tandem Mass Spectrometry.

Yuan Guo, Yuxin An, Jiaojiao Xu, Zengxuan Cai, Meijia Xu, Xiaomin Xu.

  Bongkrekic acid (BA) is a metabolite that is lethal to humans and is produced by Burkholderia gladioli pathovar cocovenenans (BGC) containing the bon gene cluster. An analytical method for BA and its stereoisomer, iso-bongkrekic acid (IBA), was established for deeply fermented rice products, such as red yeast rice and its related products, by liquid chromatography-tandem mass spectrometry (LC-MS/MS). BA and IBA in samples were extracted with 80% methanol/water containing 1% ammonia by ultrasonic assistance, cleaned by solid-phase extraction (SPE) with an anion-exchange cartridge, separated with an XBridgeTM BEH C18 chromatographic column (150 mm × 3.0 mm, 2.5 μm), measured by MS/MS, and quantified using an isotope-labeled internal standard. The influencing factors such as extraction solvents, ultrasonic extraction time and loading volume during SPE clean-up were optimized to improve the recoveries of BA and IBA. Also, the extraction efficiency between the simulated quality control and directly spiked samples, the matrix effects with the use of different chromatographic columns, the impact of co-eluting interferences under different mobile phase compositions and the conversion of BA to IBA are discussed. The linear range of BA and IBA was 0.1-50 ng/mL (equivalent to 1-500 μg/kg in the sample), with the correlation coefficient exceeding 0.999. The limits of detection and quantification were 0.3-0.5 μg/kg and 1.0-1.5 μg/kg, respectively. The average recoveries of the analytes were 88.4-107% with relative standard deviations (RSDs, n = 6) between 2.9% and 11.8% in red yeast rice and its related products under three spiking levels. This optimized method was applied to study the contamination of BA and IBA in commercially available samples. This study can provide technical support for the supervision and risk assessment of BA and IBA in red yeast rice and its related products.

Keywords:  LC-MS/MS; anion-exchange cartridge; bongkrekic acid; iso-bongkrekic acid; red yeast rice and its related products

DOI:  https://doi.org/10.3390/toxins18100407
J Chromatogr B Analyt Technol Biomed Life Sci. 2026 Oct 23. pii: S1570-0232(26)00434-4. [Epub ahead of print]1285 125345

Quantification of clofazimine, linezolid, levofloxacin, and moxifloxacin in breast milk by online solid phase extraction coupled to LC-MS/MS.

Buyisile Mkhize, Richard Court, Sandra Castel, Marian Loveday, Francesca Conradie, Gary Maartens, Anton Joubert, Edda Zangenberg, Marthinus van der Merwe, Katie Kriegler Foster, Lubbe Wiesner.

  We developed and validated a method to quantify clofazimine, linezolid, levofloxacin, and moxifloxacin in breast milk. Inconsistencies in analyte behavior necessitated the development of separate sample preparation methodologies for the less polar analyte, clofazimine, and the more polar compounds linezolid, levofloxacin, and moxifloxacin. Clofazimine was extracted via online solid-phase extraction using a Synergi Hydro-RP column with a total run time of 7 min, while the polar compounds were extracted using a Restek Viva BiPh column for a total run time of 6.50 min. Both groups were separated by liquid chromatography on an Agilent Poroshell 120 EC-C18 column. Detection was performed using tandem mass spectrometry with electrospray ionization and multiple reaction monitoring. Calibration curves fitted weighted quadratic regression equations over the ranges of 0.0477-6.00 μg/mL for clofazimine, 0.191-24.0 μg/mL for linezolid, and 0.240-30.2 μg/mL for levofloxacin and moxifloxacin. The method demonstrated precision and inter/intra-day accuracies that readily met acceptance criteria according to the FDA and EMA guidelines. The average recoveries for clofazimine, linezolid, levofloxacin, and moxifloxacin were 68.0%, 94.1%, 104.5%, and 106.0%, respectively; mean precision ranged from 0.8% to 4.7%. The robust methodology, proven to be selective and reliable when tested in different lots of breast milk, was applied to the analysis of clinical samples collected from women on treatment for drug-resistant tuberculosis. Comparison of the observed drug breast milk concentrations with maternal plasma samples taken at the same timepoints provide much-needed data regarding the exposure of second-line TB drugs in pregnant and breastfeeding women and their infants.

Keywords:  Antituberculosis drugs; Liquid chromatography with tandem mass spectrometry; Online solid phase extraction

DOI:  https://doi.org/10.1016/j.jchromb.2026.125345
Biomolecules. 2026 Sep 25. pii: 1399. [Epub ahead of print]16(10):

Detecting and Quantifying Variability in Mass Spectrometry-Based Metabolomics Datasets.

Aleesa E Chua, Heather Desaire.

  Mass spectrometry-based metabolomics approaches generate high-dimensional datasets that enable comprehensive profiling of metabolites and other biomolecules. However, these datasets are influenced by multiple sources of variability, including both the biological variation of interest and unwanted technical or systematic variation introduced throughout experimental or analytical workflows. Distinguishing between these sources of variation is important for ensuring robust and reliable downstream interpretation. This review examines commonly used approaches for the detection and quantification of variability in MS-based omics datasets, including statistical and multivariate methods such as coefficient of variation analysis, principal component analysis, variance-based metrics and other quality assessment and visualization techniques used to evaluate data structure and reproducibility. The review further highlights how these approaches can be applied to identify systematic sources of variation to support the appropriate implementation of normalization strategies. Improved detection and characterization of variability enhance data quality, reproducibility, and interpretability, which thereby support more reliable biomarker discovery and broader omics applications.

Keywords:  data analysis; mass spectrometry; metabolomics; quality control; statistics; variation; visualization

DOI:  https://doi.org/10.3390/biom16101399
J Am Soc Mass Spectrom. 2026 Oct 27.

A High-Resolution Mass Spectrometry Workflow for Xenobiotic Metabolite Discovery and Toxicity Prioritization: Disperse Orange 61 as a Case Study.

Kirsten E Overdahl, Georgia Roberts, Emily C Gentry, Suramya Waidyanatha, June Dunnick, Alan K Jarmusch.

Extensive characterization of xenobiotic metabolites remains a major challenge in mass spectrometry-based exposomics, as untargeted high-resolution mass spectrometry (HRMS) can detect extensive chemical diversity but often lacks sufficient structural annotation and prioritization strategies for unknown metabolites. Here, we developed a built-for-purpose HRMS-based workflow combining untargeted metabolomics, in silico metabolite prediction, structural annotation, and toxicity prioritization to characterize xenobiotic biotransformation products using Disperse Orange 61 (DO61) as a case study. Sprague-Dawley rats were exposed to DO61 via oral gavage, and liver, plasma, and urine samples were analyzed by ultra-high performance liquid chromatography (UHPLC) coupled to HRMS in positive and negative ionization modes. Statistically significant features were prioritized and screened against a BioTransformer-generated suspect library containing predicted Phase I, Phase II, reductive, and microbial transformations. HRMS-based annotation, supported by bromine isotope pattern analysis and MS/MS fragmentation, identified putative DO61 metabolites, while SIRIUS-derived molecular formula predictions provided additional confidence through fragmentation-based structural evaluation. The workflow experimentally confirmed reductive azo cleavage as an early DO61 transformation, producing two aromatic amine products, and revealed extensive downstream metabolism of the parent compound and both cleavage products. Computational toxicity prediction further prioritized confirmed and putatively annotated metabolites with potential mutagenic relevance for a future evaluation. This workflow demonstrates how integrating untargeted HRMS with computational approaches can facilitate metabolite discovery, improve structural annotation confidence, and prioritize metabolites for toxicological evaluation, providing a hypothesis discovery strategy for characterizing xenobiotic metabolism and supporting exposure and hazard assessment within the field of exposomics research.

DOI: https://doi.org/10.1021/jasms.6c00325
Brief Bioinform. 2026 Sep 01. pii: bbag591. [Epub ahead of print]27(5):

Data processing in proteomics and metabolomics: liquid chromatography-mass spectrometry-based omics with divergent computational paradigms.

Amy Zheng, Bin Liao, Liang Zhang, Tao Huan.

  Proteomics and metabolomics are two foundational pillars of omics research. Proteomics focuses on the large-scale, comprehensive studies of the entire set of proteins encoded by the genome. Metabolomics targets the systematic study of chemically diverse small molecules that represent the integrated biochemical output of cellular processes and organismal physiology. Although both fields rely heavily on liquid chromatographic separation coupled with mass spectrometry (LC-MS), their fundamental chemical and biological differences shape every stage of data processing and interpretation. In this review, we move beyond a descriptive comparison of existing pipelines and develop a task-level framework to understand why proteomics and metabolomics have evolved different bioinformatic paradigms despite sharing the same analytical platform. We examine how the degree of prior molecular knowledge shapes feature extraction, identification, confidence assessment, and quantification. We show that the constrained, sequence-defined nature of the proteome enables database-driven peptide identification, rigorous false discovery rate control, and increasingly standardized quantitative workflows. In contrast, we highlight how the open, chemically heterogeneous, and incompletely enumerated metabolome has required peak-shape-based feature detection, retention-time and mass-to-charge ratio-based alignment, extensive signal correction, and confidence-tiered structural annotation. By examining these workflows side by side, we identify shared challenges and field-specific bottlenecks and discuss opportunities for cross-fertilization between proteomics and metabolomics. Ultimately, this review provides a framework for an in-depth understanding of why two LC-MS-based omics fields have developed divergent computational solutions and how future bioinformatic advances may benefit both communities.

Keywords:  bioinformatics; cross-field learning; data processing; metabolomics; molecular annotation; proteomics

DOI:  https://doi.org/10.1093/bib/bbag591
Antioxidants (Basel). 2026 Oct 08. pii: 1301. [Epub ahead of print]15(10):

Measurement of Lipid Oxidation in Foods and Selected Biological Systems Using LC-MS/MS-Based Lipidomics.

Danyoung Kim, JuDong Yeo.

  Lipid oxidation is an important factor affecting food quality and oxidative stability, but conventional oxidation indices provide limited information on individual oxidation products and changes in lipid species. This review focuses on liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based approaches for lipid oxidation analysis and their applications in food and selected biological systems. LC-MS/MS provides molecular-level information on individual oxidation products and oxidized lipid species; however, its analytical reliability can be affected by hydroperoxide instability, matrix effects, limited availability of authentic standards, and variability in data processing and lipid annotation. The analytical characteristics of hydroperoxides, aldehydes, alcohols, ketones, organic acids, hydrocarbons, and oxidized complex lipids are described together with the advantages and limitations of LC-MS/MS analysis. In addition, this review compares targeted analysis with untargeted and pseudotargeted lipidomics and discusses their applications to edible oils, meat, emulsions, and oleosomes. The use of lipidomics in selected biological systems and artificial intelligence (AI)-assisted lipid analysis is also discussed. Therefore, combining validated targeted analysis and lipidomics with conventional oxidation indices may provide a more reliable and comprehensive evaluation of lipid oxidation.

Keywords:  LC-MS/MS; artificial intelligence; emulsion; lipid oxidation; lipidomics; oleosome

DOI:  https://doi.org/10.3390/antiox15101301
Methods Mol Biol. 2027 ;3083 133-162

Data-Driven Mechanistic Modeling of Untargeted Metabolome Data.

Meeri Mäkinen, Veronique Chotteau.

  Mathematical modeling can aid in understanding cell metabolism by allowing the construction of mechanistic metabolic models. The cell metabolism can be described as a biochemical reaction network. However, due to the reaction network size, identifying pathways used by the cells is challenging. Enumeration of all the possible pathways is challenging due to the number of combinations increasing exponentially with the reaction network size. Column generation (CG) is a data-driven approach for iteratively identifying a set of metabolic pathways. CG allows a reaction network of up to genome scale. In this chapter, we describe in detail how to carry out CG modeling for untargeted extracellular and intracellular metabolomic data. Metabolomics data are often scarce, and the metabolite concentrations from untargeted metabolomics are relative, posing challenges for modeling. We have demonstrated how to deal with these challenges and identify important metabolites and metabolic routes from untargeted metabolomic data [1]. Steps from initial key metabolite identification to reaction network modification, model construction, and model interpretation are explained. This allows the reader to apply the method to their own data and identify important metabolic pathways, where an interesting application can be to identify feed medium modifications to obtain better production for their mammalian cell-based bioprocess.

Keywords:  Bioproduction process modelling; CHO cells; Elementary flux modes; Mechanistic metabolic modelling; Untargeted metabolomics

DOI:  https://doi.org/10.1007/978-1-0716-5583-2_9
Talanta. 2026 Oct 17. pii: S0039-9140(26)01454-2. [Epub ahead of print]314 130798

Comprehensive characterization of regulated and emerging marine toxins by UHPLC-IM-QTOF using automated MS/MS and collision cross section measurements.

Jesús M González-Jartín, Amparo Alfonso, Rebeca Alvariño, Mercedes R Vieytes, Luis M Botana.

  A comprehensive ultra-high-performance liquid chromatography coupled to ion mobility quadrupole time-of-flight mass spectrometry (UHPLC-IM-QTOF) method was developed for the simultaneous analysis of regulated and emerging marine toxins. The approach combined accurate-mass full-scan acquisition, automated tandem mass spectrometry (MS/MS) fragmentation and ion mobility spectrometry to provide four complementary identification criteria: retention time, accurate mass, collision cross section (CCS) and diagnostic fragmentation. Auto MS/MS generated characteristic product ions for all toxin families, enabling structural confirmation of paralytic shellfish toxins, diarrhetic shellfish toxins, azaspiracids, cyclic imines, domoic acid and tetrodotoxin. Ion mobility successfully differentiated the isomeric toxins okadaic acid and dinophysistoxin-2, while simultaneous mobility-resolved fragmentation enabled confident precursor-product ion assignment and cleaner MS/MS spectra. Experimental CCS values were established, covering all major regulated marine toxin groups with excellent repeatability. The proposed workflow constitutes a powerful complementary approach to current official methods, enhancing the confirmation of regulated toxins while providing a robust platform for retrospective analysis and high-resolution mass spectrometry (HRMS)-based suspect screening of emerging marine biotoxins.

Keywords:  Biotoxins; Collision cross section (CCS); IM-QTOF; Ion mobility

DOI:  https://doi.org/10.1016/j.talanta.2026.130798
J Lipid Res. 2026 Oct 26. pii: S0022-2275(26)00209-9. [Epub ahead of print] 101179

A Comprehensive GC-MS Toolbox for Targeted and Untargeted Sterol Analysis.

Ludwig Huber, Jonathan P Sirois, Jonas Huhn, Oliver Scherf-Clavel, Stefan Berghoff, Christoph Müller.

  Sterols represent a structurally distinct class of lipophilic natural lipids defined by a rigid tetracyclic scaffold. They are essential for cellular architecture and function, serving as key structural components of biological membranes, precursors for bioactive molecules, and regulators of diverse signaling pathways. However, their high structural similarity and closely related physicochemical properties hamper chromatographic resolution, while the limited availability of reference standards restricts accurate identification and quantification. As a consequence, sterols remain underrepresented in many research areas, including human biomarker studies. To address this, we established a comprehensive sterol analytical toolbox that integrates validated commercially available and in-house synthesized reference standards and is released as an open access sterol library for the research community. The presented library comprises 110 sterols of plant, fungal, and mammalian origin, including six sterol acids, seven epoxy sterols, and 22 oxysterols. Each compound was systematically characterized by chromatographic separation on four different GC-columns, determination of relative retention times and Kováts indices, full scan electron ionization (EI) mass spectra, and optimized multiple reaction monitoring transitions for quantitative analysis. The resulting dataset enabled the establishment of sterol-specific EI-MS fragmentation signatures and retention increment principles, providing a robust framework for the reliable identification of known and previously uncharacterized sterols.

Keywords:  Kováts index; Lipids; cholesterol biosynthesis; cholesterol metabolism; ergosterol biosynthesis; oxysterol; phytosterols; steroid hormones

DOI:  https://doi.org/10.1016/j.jlr.2026.101179
Mass Spectrom Rev. 2026 Oct 29.

Mass Spectrometry Imaging-Guided Proteomics, an Emerging Frontier in Spatial Biology.

Kenneth Weke, Julian J Lum, David R Goodlett, Helena Pětrošová, Irena Dapic.

  Spatial heterogeneity is a defining feature of tissue organization, yet conventional proteomic analysis provides limited information about the spatial origins of identified proteins. Spatially guided proteomics addresses this limitation by using tissue imaging techniques to select regions of interest (ROIs) for localized analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Among the imaging modalities available for this purpose, mass spectrometry imaging (MSI) stands out for its ability to map diverse molecular species directly within tissue without predefined targets, allowing chemically distinct regions to guide tissue sampling. By bridging spatial molecular profiles with high protein coverage, MSI-guided proteomics offers comprehensive biological insight. This review examines the workflow from MSI data acquisition through ROI definition, image registration, tissue isolation, and sample preparation to LC-MS/MS analysis. We compare common MSI modalities, discuss methods for ROI isolation, and summarize advances in nanoproteomics methods that support analysis of tissue samples at the microscopic scale. We critically evaluate applications in cancer research, infectious disease, neuroscience, and environmental science. Finally, we discuss the challenges and future directions of MSI-guided proteomics. We conclude that ongoing developments in the MSI-guided proteomics workflow position it as an emerging strategy for investigating localized biological processes within heterogeneous tissues.

Keywords:  laser microdissection; limited sample; liquid chromatography tandem mass spectrometry; spatial omics; spatially guided proteomics

DOI:  https://doi.org/10.1002/mas.70048
J Nat Prod. 2026 Oct 23. 89(10): 2873-2886

Complementary Orthogonal Approaches for Metabolite Profiling of Chamaelirium luteum (False Unicorn) Root Preparations and Commercial Products.

Sarah A Barr, Wilmer H Perera, Wendy K Strangman.

  Chamaelirium luteum (L.) A. Gray (Melanthiaceae), commonly known as false unicorn, is a North American medicinal herb traditionally used for women's reproductive health. Its major bioactive constituents are open-chain steroidal saponins, a structurally distinctive compound subclass whose increased conformational flexibility may confer bioactivities distinct from common steroidal saponin scaffolds. Because C. luteum is slow-growing and primarily wild-harvested, it faces conservation concerns. Although individual metabolites, including chamaelirosides A (1) and B (2), have been characterized, commercial reference standards and extract-level authentication methods are lacking. To address this need, we developed complementary orthogonal analytical approaches integrating high-performance thin-layer chromatography (HPTLC) chemometric profiling with untargeted liquid chromatography-mass spectrometry (LC-MS) metabolomics and molecular networking. HPTLC band extraction coupled with LC-MS and nuclear magnetic resonance (NMR) enabled rapid structural verification of marker compounds while reducing analysis time and resource requirements. The workflow established robust phytochemical profiles for authenticated C. luteum materials and was subsequently applied to purchased commercial formulations. The majority of products lacked characteristic C. luteum profiles, highlighting species substitution and adulteration. The generalizable workflow and reference data presented here provide a practical framework for phytochemical characterization of botanicals containing open-chain steroidal saponins and, more broadly, for other taxa lacking authenticated reference materials.

Keywords:  GNPS2; HPTLC; LC-MS/MS; MZmine; NMR; SIRIUS; false unicorn

DOI:  https://doi.org/10.1021/acs.jnatprod.6c00810
Environ Sci Pollut Res Int. 2026 Oct 24.

Liquid chromatography-mass spectrometry approaches for analysis of polychlorinated alkanes: a review.

Laura Lazdiņa, Ingus Pērkons.

  Polychlorinated alkanes (PCAs), the primary components of technical mixtures known as chlorinated paraffins (CPs), are complex and persistent pollutants of growing environmental and analytical concern. Their widespread use and toxicological properties, particularly those of short- and medium-chain PCAs (C10-17), have prompted increased regulatory and scientific attention. This review provides a comprehensive overview of recent advances in the analysis of PCAs using liquid chromatography coupled with mass spectrometry (LC-MS), with emphasis on separation, ionization, and detection strategies. Key developments in stationary and mobile phase selection, gradient optimization, and the role of mobile phase additives in enhancing ionization are critically evaluated. Particular attention is paid to the challenges posed by the structural complexity of PCAs, including isomeric diversity and mass spectral interferences, and how they are addressed by high-resolution and tandem mass spectrometric techniques. Variability in instrumental response across carbon-chain lengths and chlorination degrees is also examined. The review highlights current methodological advancements and limitations, and outlines perspectives for improving analytical reliability.

Keywords:  Adduct formation; Chlorinated paraffins; Ionization additives; Liquid chromatography; Mass spectrometry; Persistent organic pollutants; Polychlorinated alkanes; Spectral interferences

DOI:  https://doi.org/10.1007/s11356-026-38341-3
Toxins (Basel). 2026 Oct 15. pii: 452. [Epub ahead of print]18(10):

Comparison of Two Passive Samplers for Hydrophilic and Lipophilic Phycotoxins and Expansion of Analytical Methods for Quantification Using UPLC-MS/MS.

Josh A Garber, Damian Shea, Juliette L Smith.

  The co-occurrence of phycotoxins produced by harmful algal blooms is becoming more frequent. To combat this problem, monitoring programs that can track and quantify a wide range of hydrophilic and lipophilic phycotoxins are required. A 24 h, bench-scale study was conducted to provide an initial comparison of apparent sorption and extraction recovery for 24 freshwater and marine phycotoxins from two passive samplers under controlled artificial seawater conditions. Modifications were made to previously published ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) methods to capture all phycotoxin analytes of interest in two injections. This analytical method was also evaluated alongside extraction methods for a commonly used passive sampler, a solid phase adsorption toxin tracker (SPATT), and a novel passive sampler, the composite integrated passive sampler (CIPS). SPATT contained a lipophilic resin, Diaion® HP20, whereas the CIPS is a continuous sheet with hydrophilic and lipophilic regions aimed at allowing for adsorption across a wider range of phycotoxins. A single-step extraction procedure was tested for both samplers to determine apparent extraction recoveries for all 24 phycotoxins. The CIPS seemed to produce overall higher apparent extraction recoveries of analytes, but the receiving phase generally sorbed less ng of phycotoxin during the experimental period than SPATTs and matrix effects were present. Across all lipophilic and hydrophilic phycotoxins, SPATT sorbed more than 90% of each phycotoxin from the seawater within 24 h, for all but four phycotoxins. The CIPS, however, sorbed less of each, but still more than 50% in artificial seawater for all but three phycotoxins. When considering extraction efficiency, SPATT may be better suited for hydrophilic phycotoxins, while the extraction method for CIPS appeared more efficient for lipophilic compounds, but further investigations are required to investigate potential matrix effects. The utility of the novel CIPS was preliminarily demonstrated in the laboratory, with seemingly relatively improved performance for particular phycotoxin classes (Azaspiracids, Dinophysistoxins/Pectenotoxins, Microcystins, and Brevetoxin) as compared to SPATT. The expanded UPLC methods and CIPS must be trialed in the field next to determine their applicability to monitoring, research, and management. The benchtop work, however, already suggests that users should consider the full range of phycotoxins present at an environmental site and create sampling schemes appropriate for their region given the different sorption and extraction efficiencies of these two samplers.

Keywords:  UPLC-MS/MS; cyanotoxins; harmful algal blooms; mass spectrometry; passive samplers; phycotoxins

DOI:  https://doi.org/10.3390/toxins18100452
Mar Drugs. 2026 Sep 29. pii: 343. [Epub ahead of print]24(10):

Vanadium Pentoxide-Mediated Oxidation Coupled with HPLC-MS/MS for Broad-Spectrum Screening of Paralytic Shellfish Toxins in Plasma.

Yangde Ma, Huilan Yu, Xiujie Liu, Bo Chen, Longhui Liang, Shilei Liu.

  Paralytic shellfish toxins (PSTs), potent neurotoxic alkaloids produced by marine dinoflagellates and cyanobacteria, pose severe risks to human health through contaminated seafood and water after absorption into the bloodstream. Current detection methods are limited by matrix interference or ethical concerns. Here, we report a novel screening approach using vanadium pentoxide as an oxidant to convert PSTs into characteristic oxidation products, followed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis. Under optimized conditions, vanadium pentoxide oxidizes both hydroxylated and non-hydroxylated toxins into distinct major products (P1-P7), identified by high-performance liquid chromatography-tandem high-resolution mass spectrometry (HPLC-HRMS). Vanadium pentoxide oxidation affords excellent product selectivity and, for most PSTs, superior signal intensities, enabling unambiguous differentiation of toxin subgroups. HPLC-MS/MS method in MRM mode was developed and yielded detection limits of 0.3-1.5 ng/mL for a broad spectrum of fourteen PSTs in spiked plasma, accuracy of 89.3-102.2%, and excellent repeatability with intra- and inter-day relative standard deviations (RSDs) ranging from 0.3% to 10.4%. Application of the method to samples from the First Trial OPCW (the Organisation for the Prohibition of Chemical Weapons) Biotoxin Proficiency Test successfully identified STX/neoSTX, confirming its practical utility for trace PSTs detection in complex biological matrices.

Keywords:  liquid chromatography-tandem mass spectrometry; oxidation reaction; paralytic shellfish toxins; saxitoxin

DOI:  https://doi.org/10.3390/md24100343
Int J Neonatal Screen. 2026 Oct 12. pii: 84. [Epub ahead of print]12(4):

Dried Urine Spots for Quantification of C0 (Free) Carnitine Excretion: A Validated Method for Follow-Up and Confirmatory Testing of Primary Carnitine Deficiency.

Maria van der Ham, Sacha Ferdinandusse, Mirjam Langeveld, Sabine A Fuchs, Monique G M de Sain van der Velden, On Behalf Of The Odin Study Group.

  Primary carnitine deficiency (PCD), caused by Organic Cation Transporter Novel 2 (OCTN2) deficiency, is detected by newborn screening (NBS) through low blood free carnitine (C0) concentrations. Confirmation of the diagnosis may be supported by demonstrating increased urinary C0 excretion, but urine collection in newborns is technically challenging. We developed and validated a dried urine spot (DUS) method for quantifying urinary C0 excretion as a practical, non-invasive alternative to conventional liquid urine sampling. This approach has the potential to allow parents to obtain urine at home by placing filter paper cards between the baby's skin and a dry diaper, simplifying sample collection. C0 carnitine and creatinine were quantified in 6 mm DUS punches by flow injection analysis-tandem mass spectrometry (FIA-MS/MS) following butylation. The method was analytically validated for sensitivity, precision, stability, and agreement with liquid urine measurements. The method demonstrated excellent analytical performance, with lower limits of detection (LLOD)/lower limits of quantification (LLOQ) values of 0.02/0.07 µmol/L for C0 and 0.01/0.04 mmol/L for creatinine. Normalization of C0 to creatinine reduced variability related to sampling and punch location. Both analytes remained stable in DUS for at least 10 days at room temperature and after 11 freeze-thaw cycles. C0/creatinine obtained from DUS showed excellent agreement with liquid urine (R2 > 0.9967), although concentrations were consistently lower, requiring a correction factor of 1.27 to estimate concentrations equivalent to liquid urine. DUS provides a reliable and accurate alternative to liquid urine for measuring C0 excretion in newborns. This simple, home-based sampling approach facilitates non-invasive urine collection and has the potential to support follow-up and confirmatory testing of PCD.

Keywords:  C0 (free) carnitine excretion; FIA-MS/MS; dried urine spot; newborn screening; primary carnitine deficiency

DOI:  https://doi.org/10.3390/ijns12040084
Chimia (Aarau). 2026 Oct 28. 80(10): 676-684

From LC-MS Metabolomic Profiling to AIEnabled Navigation of NPs Chemical Space: Recent Advances and Emerging Directions.

Jean-Luc Wolfender, Loïc Le Grégam, Emerson Ferreira Queiroz.

  Natural products (NPs) occupy a unique region of chemical space and continue to provide privileged scaffolds for drug discovery, chemical ecology, and biotechnology. However, the exploration of NP diversity remains constrained by the complexity of biological extracts, the low annotation rate of LC-MS features, and the rediscovery of known metabolites. Recent advances in LC-HRMS/MS-based metabolomics, coupled with expanding spectral and structural databases, molecular networking, and in silico annotation methods, have considerably improved the characterization of complex metabolomes and facilitated large-scale exploration of natural chemical space. Simultaneously, artificial intelligence (AI) and machine-learning approaches are enhancing metabolite annotation, chemical classification, and prioritization, while knowledge graph technologies enable the integration of chemical, taxonomic, biological, and ecological information into interoperable, AI-ready frameworks. This mini-review highlights recent developments that support a transition from conventional metabolite annotation towards effective navigation of NP chemical space. We discuss the role of open data resources, computational metabolomics, knowledge-driven data integration, and emerging AI-assisted tools in accelerating NP discovery. We also examine how biotransformation and chemoenzymatic diversification can extend the boundaries of natural chemical space by generating nature-inspired molecules and previously inaccessible scaffolds. Together, these approaches are paving the way towards a more predictive, integrative, and data-driven paradigm for NP research and bioactive compound discovery.

Keywords:  Artificial intelligence; Biotransformation; Knowledge graphs; Metabolomics; Natural products

DOI:  https://doi.org/10.2533/chimia.2026.676
bioRxiv. 2026 Sep 02. pii: 2026.08.27.747606. [Epub ahead of print]

spatialMET: an open and scalable framework for spatial metabolomics analysis.

Yonatan Ayalew Mekonnen, Oscar E Ospina, Vanessa Rubio, Eric Welsh, Reaz Uddin, Hayley D Ackerman, Alex Soupir, James E Cox, Brooke L Fridley, Elsa R Flores, John Koomen, Paul A Stewart.

Mass spectrometry imaging (MSI) enables spatially resolved metabolomics in intact tissue sections, but analysis remains challenging at scale. Existing MSI workflows often require users to combine multiple software tools, while others rely on proprietary vendor software that limits interoperability and reproducibility. To address these challenges, we developed spatialMET, an open-source framework that provides an end-to-end workflow for MSI analysis. spatialMET provides a unified platform for preprocessing, spatial domain detection, and visualization. Downstream analyses include differential abundance testing, spatial autocorrelation and gradient analysis, dimensionality reduction, and correlation network analysis. Spatial domain detection uses hcdist, a C-based hierarchical clustering implementation that substantially reduces runtime and memory use relative to existing R-based approaches. spatialMET can be run through an interactive R Shiny application or as a standalone command-line workflow for larger datasets or high-performance computing environments. Applied to mouse small cell lung cancer MALDI-MSI data containing 284,673 pixels, spatialMET identified tumor-associated, stromal, and adjacent lung spatial domains that aligned with matched histology. Differential abundance analysis identified 117 m/z features that differed between tumor and stromal regions, while spatial autocorrelation analyses revealed spatially structured abundance patterns. Applying spatialMET to mouse lung adenocarcinoma data from an entire lung lobe containing 338,477 pixels further demonstrated scalability and captured spatial heterogeneity across tumor and surrounding lung tissue. In summary, spatialMET provides a scalable, open-source framework for end-to-end spatial metabolomics analysis, and it is distributed as a Docker container for reproducible deployment. Source code and installation instructions are available at https://github.com/biodatalab/spatialMET.

DOI: https://doi.org/10.64898/2026.08.27.747606
Talanta. 2026 Oct 24. pii: S0039-9140(26)01462-1. [Epub ahead of print]314 130806

Quantification of multi-class pesticides in wipes dust by liquid chromatography - mass spectrometry: development and application in rural households.

Eloïse Brillard, Sabrina Gaba, Vanessa Policarpo, Nicolas Venisse, Antoine Dupuis, Sandrine Lefeuvre.

  Pesticides used in agricultural or domestic activities contaminate the outdoor environment, and subsequently infiltrate homes, where they accumulate in indoor dust. Household dust may serve as a useful proxy for assessing human exposure to pesticide residues. However, simultaneously quantifying a wide range of molecules with diverse chemical properties remains analytically challenging. This study developed and validated a liquid chromatography-mass spectrometry method to quantify 95 pesticides from different chemical families (neonicotinoids, azoles, organophosphates, carbamates, organochlorines) in wipe-collected dust samples. Solvent optimization identified ethyl acetate as the most effective for extraction. Quantification relied on linear regression with calibration ranges of 0.052 to 1.67 μg/g of dust for 81 pesticides and 0.167 to 1.67 μg/g of dust for 14 pesticides. Method validation assessed limit of quantification (LOQ), precision, accuracy, carry-over, dilution integrity, matrix effects (ME) and recovery, following European Medicines Agency guidelines. Intra- and inter day-precision and accuracy were lower than 20% at LOQ and 15% for higher QC levels. ME due to ion suppression were corrected using internal standards. The validated method was applied to dust collected from households in the LTSER Zone Atelier Plaine & Val de Sèvre (France) by rubbing a 100 cm2 wipe over a 20 × 20 cm template. The most frequently detected compounds were insecticides imidacloprid, chlorpyrifos, and the fungicide azoxystrobin. This rapid, cost-effective, and easy-to-implement wipe method provides a valuable tool for assessing indoor pesticide contamination. Further studies should explore whether indoor dust concentrations reliably reflect internal human exposure.

Keywords:  Biomonitoring; Dust; Mass spectrometry; Pesticides; Wipe

DOI:  https://doi.org/10.1016/j.talanta.2026.130806
Toxics. 2026 Oct 01. pii: 884. [Epub ahead of print]14(10):

Analytical Validation of a Multielement ICP-MS Method for Human Serum and Its Application to Trace Element Biomonitoring in Hemodialysis Patients.

Sara Valderrama Sanz, Raquel Sánchez Romero, Ricardo Molina Gasset, José Luis Todolí Torró.

  Reliable determination of trace elements in human serum is essential for clinical assessment, toxicological investigations and human biomonitoring. This study describes the development and analytical validation of a multielement inductively coupled plasma mass spectrometry (ICP-MS) method for the simultaneous determination of essential and potentially toxic trace elements in human serum (Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Ba, Bi) using a simple direct-dilution procedure with 1% (v/v) nitric acid. Method validation included assessment of linearity, limits of detection and quantification, carry-over, precision, trueness, measurement uncertainty and analyte stability. Calibration curves showed excellent linearity, with coefficients of determination (R2) ranging from 0.9993 to 1.0000 across analyte-specific calibration ranges of 0-10, 0-50, and 0-500 µg L-1. Repeatability ranged from 0.69% (Cu) to 14.5% (Ba), while intermediate precision ranged from 1.32% (Zn) to 81.1% (Cd and Bi at low concentrations). Recoveries obtained using certified serum reference materials ranged from 55% (V) to 206% (Bi) across the evaluated conditions. Meanwhile, limits of detection ranged from 0.01 (V) to 0.16 (Cu) µg L-1. Measurement uncertainty was estimated following the EURACHEM/CITAC and GUM recommendations, identifying repeatability as the principal contributor to the overall uncertainty budget. The method was successfully applied to serum samples from healthy individuals and patients undergoing chronic hemodialysis. The proposed methodology combines simple sample preparation with comprehensive metrological characterisation, providing practical approach multielement serum analysis and its application to trace-element biomonitoring investigations.

Keywords:  ICP–MS; analytical validation; biomonitoring; human serum; measurement uncertainty; trace elements

DOI:  https://doi.org/10.3390/toxics14100884
Anal Methods. 2026 Oct 30.

When nucleosides interfere with pyrimidine base quantification. Example of dihydropyrimidine dehydrogenase phenotyping.

Manon Launay, Fabienne Thomas, Jérôme Guitton.

Dihydropyrimidine dehydrogenase (DPD) phenotyping based on plasma uracil (U) and dihydrouracil (UH2) concentrations is widely used before administration of chemotherapeutic agent 5-fluorouracil. However, analytical and physiological factors may compromise its reliability. We investigated potential analytical biases affecting U and UH2 quantification using liquid chromatography-mass spectrometry (LC-MS/MS) methods, combined with different sample preparation procedures, including liquid-liquid extraction and protein precipitation with perchloric acid (PCA), acetonitrile (ACN), and trichloroacetic acid. Incomplete chromatographic separation led to UH2 overestimation due to in-source fragmentation of endogenous compounds, particularly dihydrouridine (DhUrd). This bias was amplified in patients with renal impairment, where DhUrd accumulates. Protein precipitation with PCA resulted in marked increases in both U and UH2 concentrations compared with ACN or liquid-liquid extraction. Mechanistic investigations demonstrated that PCA induces chemical conversion of DhUrd into UH2 and partial conversion of uridine (Urd) into U, rather than improving analyte recovery from protein binding as previously described. ACN precipitation was sufficient to release protein-bound U and UH2, with negligible residuals. Other sources of interference (cytosine, nucleotides, and RNA) contributed minimally. Analytical interferences and sample preparation artifacts significantly impact U and UH2 quantification and may lead to misinterpretation of DPD phenotyping results. Established UH2/U ratio decision thresholds may require re-evaluation using harmonized analytical methods accounting for endogenous interferences.

DOI: https://doi.org/10.1039/d6ay01535b
Toxins (Basel). 2026 Oct 19. pii: 455. [Epub ahead of print]18(10):

Recent Advances in the Enantiomeric Separation of Tropane Alkaloids by Liquid Chromatography: Analytical Strategies and Applications in Pharmaceutical, Biological, and Food Samples.

Fernando L Vera-Baquero, Lorena González-Gómez, Isabel Sierra, Sonia Morante-Zarcero.

  This review examines recent advances in the enantiomeric separation of tropane alkaloids (TAs), focusing on atropine, a racemic mixture of (+)- and (-)-hyoscyamine whose enantiomers differ significantly in pharmacological activity, with (-)-hyoscyamine being the more potent antimuscarinic agent. Enantiomeric purity and racemisation control are therefore essential in pharmaceutical formulations, biological samples, and food, where TAs are regulated contaminants due to their toxicological effects. The review covers analytical strategies reported from 2010 to 2026, with emphasis on high-performance liquid chromatography (HPLC), often coupled with tandem mass spectrometry (MS/MS) to improve sensitivity and selectivity. Polysaccharide-based chiral stationary phases operated in normal-phase or polar organic modes, usually with amine additives, represent the most widely employed approach. Protein-, cyclodextrin-, and antibiotic-based chiral selectors have also demonstrated successful enantiomeric resolution. Sample preparation is particularly challenging for food matrices, requiring efficient extraction and clean-up while preventing enantiomeric racemisation. Published strategies include solid-phase extraction (SPE), matrix solid-phase dispersion (MSPD), and QuEChERS protocols. Despite significant analytical advances, chiral analysis of TAs in foods remains underexplored. Recent studies have reported (-)-hyoscyamine concentrations exceeding regulatory limits in herbal infusions, underscoring the need for further research to support European Food Safety Authority (EFSA) recommendations and improve consumer risk assessment.

Keywords:  atropine; chiral analysis; chiral liquid chromatography; chiral stationary phases; food contaminants; hyoscyamine; racemisation; sample preparation

DOI:  https://doi.org/10.3390/toxins18100455
J Chromatogr A. 2026 Oct 21. pii: S0021-9673(26)00893-9. [Epub ahead of print]1790 467567

Rapid ultrasound-assisted enzymatic hydrolysis coupled with LC-MS/MS for sensitive detection of tyrosine adducts in OPNAs-exposed plants.

Hongqian Mo, Linlin Kong, Jinjuan Xue, Yongqi Li, Yongcun Yang, Jia Chen, Qin Liu, Yulong Liu, Yanqin Liu, Jianfeng Wu, Zhiyong Nie, Bin Xu, Zhi Li, Bo Ma, Yiling Liu, Lei Guo, Hua Xu, Jianwei Xie.

  The illegal use of organophosphorus nerve agents (OPNAs) poses a severe threat to public safety, highlighting the urgent need for rapid and sensitive methods for exposure tracing. To address the ethical constraints associated with traditional biomedical samples and the time-consuming preparation of plant samples, this study developed an analytical method based on rapid ultrasound-assisted enzymatic hydrolysis (RUEH), solid-phase extraction (SPE) purification, and isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the identification of OPNAs tyrosine adducts (OPNAs-Tyr) formed in OPNAs-exposed plants. Key parameters including enzyme dosage, ultrasonic hydrolysis time, and amplitude were systematically optimized, achieving efficient enzymatic hydrolysis within 20 min and substantially reducing the sample preparation duration. D5-labeled O-ethyl N,N-dimethylphosphoramidocyanidyl-l-tyrosine (D5-GA-Tyr) was adopted as a stable isotope internal standard to compensate for plant matrix-induced ion suppression. In Arabidopsis thaliana, the method enabled detection of GD-Tyr, VX-Tyr, and GA-Tyr at minimum exposure doses of 50 ng/g, 500 ng/g, and 1000 ng/g per plant, respectively. Quantification was linear over the tested exposure range (r2>0.99), with intra- and inter-day accuracy of 84.0%-96.3% and RSD ≤ 13.5%; the adducts were stable in processed samples at 4 °C for 48 h (RSD < 9.3%). Real sample analysis confirmed that the method could detect target adducts in OPNAs-exposed Arabidopsis thaliana and Rice. Furthermore, it is applicable to both freeze-dried leaf (FDL) and fresh leaf (FL) samples and offers a long detection window. Compared with traditional approaches, this method is simple to operate and less time-consuming, requiring no specialized biomedical background for implementation. Thus, it provides a novel and reliable analytical platform for environmental tracing of OPNAs exposure and forensic investigations, demonstrating considerable practical value.

Keywords:  LC-MS/MS; Organophosphorus nerve agent; Plant exposure biomarker; Tyrosine adduct; Ultrasound-assisted enzymatic hydrolysis

DOI:  https://doi.org/10.1016/j.chroma.2026.467567
J Fungi (Basel). 2026 Oct 07. pii: 749. [Epub ahead of print]12(10):

Mass Spectrometry Imaging for Mapping the Spatial Distribution of Bioactive Compounds in Medicinal Fungi: Applications, Challenges, and Future Perspectives.

Hui Fan, Suzhen Dong, Yun Zhao.

  Mass spectrometry imaging (MSI), featuring label-free detection, minimal sample pretreatment, and simultaneous multi-constituent analysis, overcomes the loss of spatial information inherent in conventional homogenization-extraction methods, enabling in situ visualization of bioactive constituents. This review systematically summarizes the recent advances and future perspectives of MSI in medicinal fungi, highlighting typical applications in Basidiomycota (e.g., Lentinula edodes, Ganoderma spp.) and Ascomycota (e.g., Ophiocordyceps sinensis, Cordyceps cicadae), which demonstrate the expansion of MSI from fundamental spatial metabolite localization to cultivar authentication and informing biosynthetic pathway investigations. We further analyze the critical challenges in medicinal fungal sample preparation-such as irregular morphological sizes and heterogeneous tissue structures-along with their resolution strategies. Subsequently, we outline the future directions of MSI, including ultra-high-resolution imaging, ion mobility integration, and spatial multi-omics fusion. Ultimately, MSI is propelling medicinal fungi research into a new era of "spatial metabolomics," providing a crucial molecular spatial perspective for the precise exploitation of fungal resources, quality control, and the deep decoding of biosynthetic mechanisms.

Keywords:  bioactive compounds; mass spectrometry imaging (MSI); medicinal fungi; sample preparation; spatial distribution

DOI:  https://doi.org/10.3390/jof12100749
Toxins (Basel). 2026 Oct 15. pii: 446. [Epub ahead of print]18(10):

Validation of a HILIC-LC-MS/MS Method for Simultaneous Determination of Paralytic Shellfish Toxins and Tetrodotoxins in Multiple Marine Matrices: The Critical Role of Matrix Effects.

Dario Lucchetti, Daniela Delfino, Marta Senofonte, Laura Spinaci, Rocco Baccelliere, Alessandro Ubaldi, Francesca Longo.

  The presence and accumulation of marine biotoxins, including paralytic shellfish toxins (PSTs) and tetrodotoxin (TTX) analogues, in marine organisms poses a significant food safety concern. This study describes the validation of a quantitative confirmatory HILIC-LC-MS/MS method for the simultaneous determination of a broad panel of marine toxins in four matrices: mussels, clams, sea snails, and sea urchins. The method covered 17 target compounds, including TTX analogues (TTX, 4-epiTTX, and 4.9-anhTTX), saxitoxin and analogues (STX, dcSTX, NEO, and dcNEO), gonyautoxins (GTX 1-4, GTX 2-3, GTX 5, GTX 6, and dcGTX 2-3), and sulfocarbamoyl toxins C1-C2. Particular attention was devoted to the evaluation of matrix effects (ME), a critical factor affecting LC-MS/MS quantification. The method was validated according to SANTE/11312/2021 guidelines, showing satisfactory selectivity, precision (RSD ≤ 20%), and accuracy (recoveries within 70-120%). Significant matrix-dependent signal suppression and enhancement were observed among the investigated species. Matrix-matched calibration enabled reliable quantification in mussels, clams, and sea snails, whereas sea urchin samples showed greater analytical complexity. The validated method provides a robust approach for the determination of PSTs and TTX analogues in different marine organisms and supports its application in official monitoring programs.

Keywords:  HILIC–LC–MS/MS; marine biotoxins; matrix effects; paralytic shellfish toxins; tetrodotoxin analogues

DOI:  https://doi.org/10.3390/toxins18100446
Anal Chem. 2026 Oct 27. 98(42): 29854-29862

Identification of Microplastics by Calcined Sand Assisted Ambient Laser Desorption Electrospray Ionization Mass Spectrometry.

Xi Xu, Huafu Pei, Qingfu Zhang, Zhiyu Yang, Wen Su, Zhongyan Zhou, Na Wang, Lei Yue.

Electrospray ionization (ESI) and laser desorption ionization (LDI) exhibit inherent limitations when applied as standalone ion sources for the mass spectrometric analysis of microplastics (MPs). Herein, we report an ambient laser desorption electrospray ionization mass spectrometry platform, CSAA-LESI-MS, using low-cost, readily available, and eco-friendly calcined sand as the matrix. This system achieves qualitative and quantitative identification of MPs with varied optical and physicochemical characteristics, including strongly and weakly light-absorbing, polar and nonpolar MPs. Efficient ionization of all analyzed polymers was achieved within 1.2 s, affording nanogram-level limits of detection (LODs) and limits of quantification (LOQs) with correlation coefficients (R2) all exceeding 0.98. Seven representative polymer classes, including polyethylene (PE), polypropylene (PP), polyamide 6 (PA6), poly(methyl methacrylate) (PMMA), poly(ethylene terephthalate) (PET), polylactic acid (PLA), and poly(oxymethylene) (POM), yielded abundant, well-resolved backbone-specific fingerprint spectra. A total of 15 suspected particles were further distinguished successfully by PPMC-based spectral matching against polymer reference libraries. The CSAA-LESI-MS method provides a versatile, economical, and precise ambient mass spectrometry approach feasible for environmental MP analysis.

DOI: https://doi.org/10.1021/acs.analchem.6c05051
ACS Meas Sci Au. 2026 Oct 21. 6(5): 1537-1548

Rapid Screening of Aldehydes by SICRIT-HRMS: Understanding Ionization Behavior in Breath Analysis.

Thibault Massenet, Shahd Abuhelal, Leila Rastegar, Amar Rai, Sopika Toumazi, Jean-François Focant, Zoltan Takats, Salman Siddiqui, Pierre-Hugues Stefanuto.

  Exhaled breath aldehydes represent clinically relevant biomarkers of oxidative stress and lipid peroxidation, yet their reliable online detection remains analytically challenging due to their trace concentrations, chemical reactivity, and structural similarity. This study highlights Soft Ionization by Chemical Reaction in Transfer coupled to high-resolution cyclic ion mobility mass spectrometry (SICRIT-cIMS-HRMS) for the direct detection and characterization of 16 clinically relevant volatile aldehydes in exhaled breath. A controlled offline spiking methodology using Tedlar sampling bags was developed, enabling systematic investigation of ionization behavior under realistic breath matrix conditions. Comparative analysis in ultrapure nitrogen and exhaled breath matrices revealed that SICRIT preferentially generates protonated [M+H]+, dehydrated [M+H-H2O]+, and oxidation-derived species, with exhaled breath shifting ionization patterns toward oxygen-containing adducts. Ionization competition from N,N-dimethylacetamide, a Tedlar bag contaminant, was identified and mitigated through standardized bag usage protocols. Quantitative assessment demonstrated good linearity (R2 ≥ 0.99 for 13 aldehydes), with LOD values ranging from 1.33 to 25.13 ppbv. Intraday variability was low across all adducts (CV < 11%), while interday variability was significantly lower for [M+H]+ species (CV < 13%) compared to oxidation-derived adducts, establishing protonated ions as the preferred targets for long-term biomarker monitoring. Cyclic ion mobility separation was evaluated for isomer differentiation. Although tentative separation of 2-ethylhexanal and octanal was observed, sensitivity losses approaching 3 orders of magnitude were encountered, likely attributed to instrument geometry and traveling wave-based ion transmission. Nevertheless, the demonstrated ability of ion mobility to discriminate VOCs from chemical noise and isobaric interferences is encouraging for future developments. This work establishes a fundamental understanding of SICRIT ionization mechanisms in complex breath matrices and identifies key analytical parameters for future method development, validation, and clinical implementation, notably motivating the investigation of SICRIT ionization mechanisms and the use of linear mobility systems for improved aldehyde isomer discrimination in respiratory disease monitoring.

Keywords:  Cyclic Ion Mobility; Online Exhaled Breath Analysis; Respiratory Disease Monitoring; SICRIT Ionization; Volatile Aldehydes

DOI:  https://doi.org/10.1021/acsmeasuresciau.6c00102
Foods. 2026 Oct 10. pii: 3598. [Epub ahead of print]15(20):

Determination of Pyrrolizidine Alkaloids in Tea and Herbal Infusions by LC-MS/MS.

Ana Catarina Sousa, Daniela Pereira, Ana R L Ribeiro, Virgínia M F Gonçalves, Inês Pádua, Cláudia Ribeiro, Sandra Leal.

  Pyrrolizidine alkaloids (PAs) and N-oxides (PANOs) are food-safety hazards subject to regulatory limits, and their occurrence in teas and herbal infusions (THI) represents a dietary route. This study aimed to develop and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determining five PAs and their PANOs in THI. Samples were extracted using hot acidified water to enhance PAs and PANOs extraction and subjected to solid-phase extraction (SPE) for clean-up and analyte preconcentration. Chromatographic separation was performed on a Luna® PFP (2) 3 µm 100 Å column using a gradient of 10 mM ammonium formate with 0.1% formic acid in water, ethanol, and methanol. The method was validated according to international guidelines, achieving detection and quantification limits of 0.41-6.60 ng/g and 1.25-20.0 ng/g. It was applied to 53 THI samples from five European countries, primarily from Portugal as a pilot monitoring study. N-oxides were the predominant form, with senecionine-N-oxide, heliotrine-N-oxide, and retrorsine-N-oxide most frequently detected in Portuguese-marketed products. The total target PA/PANO content was approximately twofold higher in herbal infusions than in teas, with chamomile showing the highest levels, followed by lemon verbena. The validated method provides a sensitive and suitable tool for preliminary assessment of PAs and PANOs in THI.

Keywords:  food contaminants; food safety; food supply; human health; plant toxins; pyrrolizidine alkaloids

DOI:  https://doi.org/10.3390/foods15203598
Methods Mol Biol. 2027 ;3089 427-440

Spatial Lipidomic Analysis Using Secondary Ion Mass Spectrometry (SIMS).

Simon Uzoni, John S Fletcher, Noora Neittaanmäki.

  Secondary ion mass spectrometry (SIMS) produces a mass spectral image of a sample, where each pixel in the image contains a mass spectrum from which chemical information can be extracted to provide maps of different molecules of interest. Alternatively, a chemical fingerprint of regions of interest in the image/sample can be extracted. The mass spectral image can be correlated with histological images to better understand the spatial chemistry associated with the different cell types/regions of the sample.

Keywords:  Biomarkers; Imaging; Lipidomics; Lipids; Metabolites; Secondary ion mass spectrometry (SIMS); Tissue sections

DOI:  https://doi.org/10.1007/978-1-0716-5619-8_30
Int J Mol Sci. 2026 Oct 19. pii: 9285. [Epub ahead of print]27(20):

Natural Antioxidant-Derived Compounds and Materials as Emerging MALDI Matrices: Applications, Evidence, and Perspectives.

Katarzyna Bania, Dorota Bartusik-Aebisher, Klaudia Dynarowicz, Barbara Smolak, David Aebisher.

  Antioxidants constitute a chemically diverse group of compounds that are widely studied in food, natural products, and biological systems, creating a continuing need for analytical methods capable of their reliable characterization. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) provides rapid molecular analysis with minimal sample preparation and has been increasingly applied to low-molecular-weight compounds, natural products, food constituents, and biological samples. However, the analysis of small molecules by MALDI-MS is often limited by matrix-derived background signals, differences in ionization efficiency, heterogeneous crystallization, and difficulties in achieving reliable quantitative measurements, highlighting the need for alternative matrix systems with improved and more controllable analytical properties. In this context, naturally occurring antioxidants are of particular interest because many possess aromatic and conjugated structures, UV-absorbing groups, acid-base and redox properties, and functional groups capable of matrix-analyte interactions, which may support their function as MALDI matrices. This review summarizes the use of MALDI-MS for the analysis of antioxidant compounds in purified samples, plant extracts, food products, and biological materials, while critically evaluating the emerging concept of using naturally occurring antioxidants as alternative MALDI matrices. Particular emphasis is placed on the structural and physicochemical features relevant to matrix performance, including aromaticity, UV absorption, acid-base properties, redox behavior, crystallization, and matrix-analyte interactions. Conventional organic matrices are discussed alongside emerging alternatives, including ionic liquid matrices, nanomaterial-based systems, carbon-based materials, and matrix-free approaches. Importantly, the available evidence indicates that only a limited number of natural antioxidant-derived compounds and materials have been experimentally demonstrated as MALDI matrices, whereas evidence for other candidates remains preliminary or theoretical. Their potential analytical value is further considered in relation to reproducibility, background interference, matrix selectivity, and quantitative performance, together with future opportunities involving rational matrix design, mass spectrometry imaging, and computational approaches. Natural antioxidant-derived compounds and materials therefore represent an emerging and still insufficiently explored class of MALDI matrices that could expand the range of matrix chemistries available for small-molecule analysis, although their analytical value will ultimately depend on compound-specific experimental validation rather than antioxidant activity alone.

Keywords:  MALDI matrices; MALDI-MS; MALDI-TOF-MS; alternative matrices; antioxidants; flavonoids; low-molecular-weight compounds; mass spectrometry imaging; natural products; phenolic compounds

DOI:  https://doi.org/10.3390/ijms27209285