bims-metlip Biomed News
on Methods and protocols in metabolomics and lipidomics
Issue of 2026–02–22
forty-two papers selected by
Sofia Costa, Matterworks
  1. A Robust LC-MS/MS Bioanalytical Strategy for Simultaneous Quantification of Tramadol HCl and Dexketoprofen Trometamol and Its Use in Pharmacokinetic Studies.
  2. An isotope dilution-liquid chromatography-tandem mass spectrometry-based candidate reference measurement procedure for the quantification of testosterone in human serum and plasma.
  3. Development and validation of a robust UPLC-MS/MS method for the analysis of polyamines in cells, biofluids and tissues.
  4. An Open-Source Platform for Reference Data-Driven Analysis of Untargeted Metabolomics.
  5. PNA-HPLC and Hybrid LC-MS/MS as Complementary Platforms for Bioanalysis of Next-Generation Nucleic Acid Therapeutics.
  6. Alkyne lipids as tracers of lipid metabolism.
  7. Scalable Incremental Clustering for Tandem Mass Spectra in Untargeted Metabolomics.
  8. A clean-up method to remove taurine conjugated bile acid isomers interference for perfluorooctane sulfonate (PFOS) analysis in biotic matrices by isotope dilution LC-MS/MS and investigation of other MRMs interference.
  9. Advances in Analytical Strategies for Precise Quantification of Topoisomerase Inhibitors: Current Trends and Future Directions.
  10. Visualization of single-cell lipidomes with MALDI-MSI.
  11. Profiling of Low-Abundance Branched-Chain Fatty Acids via Radical Directed Dissociation Tandem Mass Spectrometry.
  12. Development of an LC-MS/MS method for amantadine detection in human plasma using ZIF-8 as adsorbent and pharmacokinetic investigation.
  13. High-resolution sphingolipid analysis in vitro using LC-qToF MS.
  14. Trifluoromethylphenyl-Induced Specific Acyl Chain Fragmentation in Liquid Chromatography Mass Spectrometry for Free Furan Fatty Acid Screening in Fish Oils.
  15. Reliable LC-MS/MS method integrated with a linear retention index approach for multiresidue pesticide analysis in hemp seed oil.
  16. MetaboliteAnnotator: AI-Assisted Name Harmonization and Metadata Enrichment Tool for Metabolomics.
  17. Coupling micro-flow liquid chromatography with Q-Orbitrap high-resolution mass spectrometry for greener, comprehensive pesticide residue analysis in fruits and vegetables.
  18. Advances in LC-MS/MS methods and sample preparation strategies for therapeutic drug monitoring of immunosuppressive drugs.
  19. Mass spectrometry-based lipid analysis in NPC1 disease: Methods for phosphoinositide quantification, lipid imaging, and myelin lipid profiling.
  20. Supercritical fluid chromatography hyphenated with dielectric barrier discharge ionization mass spectrometry: A universal approach to analysis of complex plant extracts.
  21. Novel spectral comparison for chlorinated paraffin analysis using planar solid phase extraction coupled to high-resolution mass spectrometry.
  22. Multi-structural profiling of neutral glycosphingolipids using selective enrichment and the Paternò-Büchi derivatization.
  23. GC-FID Quantification of Methanol, Ethanol, 2-Propanol, Acetone, Ethylene Glycol, Diethylene Glycol, 1,2-Propylene Glycol and 1,3-Propylene Glycol in Plasma.
  24. Chemometrics-assisted validation of a high-throughput method for quantitative analysis of multiclass phytohormones across plant matrices by UHPLC-QQQ-MS/MS for targeted metabolomics.
  25. Imaging mammalian lipids using desorption electrospray ionization mass spectrometry: A review.
  26. RNA sample preparation strategies for mass spectrometry sequencing of the epitranscriptome and therapeutic RNAs: A review.
  27. Strategies to minimize artificial lipid oxidation in mass spectrometry based epilipidomics analysis.
  28. FastCCS: A Deep Learning Framework for Accurate Collision Cross-Section Prediction from SMILES with Broad Applications in Cheminformatics and Omics.
  29. Development and Clinical Application of a Simultaneous Liquid Chromatography-Tandem Mass Spectrometry Method for Patients with Graft-versus-Host Disease to Quantify the Plasma Concentrations of Ruxolitinib and Posaconazole.
  30. A simple and highly sensitive LC-MS/MS bioanalytical method for phosphorodiamidate morpholino oligonucleotides in plasma.
  31. Detection, imaging and quantification of phosphoinositides using ion chromatography suppressed conductivity and mass spectrometry imaging.
  32. OctoChemDB: An Aggregated Database for Small Molecule Identification Using High-Resolution MS Data.
  33. MOESIopt: An Integrated Computational Framework for Automated Restoration of Suboptimal Mass Spectrometry and Optical Emission Spectrometry Images.
  34. Transposition of the Complementary Developing Solvent Technique to Flash Chromatography: A Structured Step-Based Fractionation Strategy for Complex Plant Extracts.
  35. Mixed sorbent in miniaturized stir bar sorptive dispersive microextraction for the determination of gut microbiome metabolites in plasma samples.
  36. Exploring Approaches for Accelerated Mass Spectrometric Detection of Fluorochemicals from Aqueous Solutions Using Indirect, Adsorbent-Facilitated Desorption Ionization.
  37. Comparative analysis of metabolites in different Areca inflorescence tissues based on spatial metabolomics.
  38. Rapid magnetic solid-phase extraction approach employing a modified graphene oxide nanomaterial for the determination of 20 pharmaceuticals and transformation products in treated urban wastewater.
  39. Measuring nutrient content in human milk: are we there yet?
  40. A multi-functional effervescent tablet for one-pot effervescent/derivatization/extraction: An integrated strategy for sulfonamide residue analysis.
  41. Rapid differentiation of D/L-homocysteine, D/L-homocystine, and S-allyl-D/L-cysteine using ion mobility-mass spectrometry.
  42. Metabolic labeling of glycerophospholipids.
  1. Biomed Chromatogr. 2026 Apr;40(4): e70398
    A Robust LC-MS/MS Bioanalytical Strategy for Simultaneous Quantification of Tramadol HCl and Dexketoprofen Trometamol and Its Use in Pharmacokinetic Studies.
    Adusumalli Srinivasa Rao, P Bangaraiah, Sathish Kumar Konidala.
      This study reports the first bioanalytical method for simultaneous estimation of Tramadol HCl and dexketoprofen trometamol in rat plasma using Tapentadol as an internal standard. A validated LC-MS/MS method was developed following USFDA guidelines. Analytes were extracted from plasma by protein precipitation technique using acetonitrile. Chromatographic separation was achieved on a Waters Symmetry Shield RP-18 column (250 × 4.6 mm, 5 μm) with an isocratic mobile phase of acetonitrile and 0.1% formic acid in HPLC grade water (30:70 v/v) at a flow rate of 1.0 mL/min, yielding a 7-min runtime. Detection was performed using electrospray ionization with ion transitions of m/z 222.3398 → 70.0307 for Tapentadol, m/z 264.4351 → 96.4527 for Tramadol HCl, and m/z 376.4239 → 100.4520 for dexketoprofen trometamol. The method showed good accuracy, with mean recoveries of 92.79%-98.15% for Tramadol HCl and 91.78%-98.37% for dexketoprofen trometamol. Excellent linearity was obtained, with r2 values of 0.99983 (22.5-900 ng/mL) and 0.99963 (7.5-300 ng/mL), respectively. All validation parameters met acceptable criteria. The method is suitable for evaluating pharmacokinetic parameters that indicate drug efficacy and safety.
    Keywords:  LC‐MS/MS; Tramadol HCl; USFDA guidelines; dexketoprofen trometamol; rat plasma
    DOI:  https://doi.org/10.1002/bmc.70398
  2. Clin Chem Lab Med. 2026 Feb 06.
    An isotope dilution-liquid chromatography-tandem mass spectrometry-based candidate reference measurement procedure for the quantification of testosterone in human serum and plasma.
    Elie Fux, Rupert Schmid, Neeraj Singh, Sandra Fleischer, Friederike Bauland, Daniel Köppl, Alexander Gaudl, Andrea Geistanger, Uta Ceglarek, Manfred Rauh, Christian Geletneky, Judith Taibon.
       OBJECTIVES: This study presents a candidate reference measurement procedure (RMP) for testosterone quantification in human serum and plasma, utilizing isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC MS/MS).
    METHODS: The developed LC-MS/MS method employs a two-dimensional heart-cut LC approach combined with solid-phase extraction (SPE) for sample clean-up, ensuring accurate testosterone analysis in human serum and plasma. Traceability to SI units was achieved by using a primary reference material listed by the Joint Committee on Traceability in Laboratory Medicine (JCTLM). An alternative quantification approach using qNMR content determination is also described. Assay validation followed current guidelines, assessing selectivity and specificity with spiked serum samples. Matrix effects were evaluated through post-column infusion experiments and comparison of standard line slopes. Precision, accuracy, and trueness were determined through an extensive 5-day protocol. Measurement uncertainty for reference value assignment was evaluated as per the Guide to the Expression of Uncertainty in Measurement (GUM), with three individual sample preparations performed on at least two different days.
    RESULTS: The RMP facilitated testosterone quantification in the range of 27.7 pmol/L (8.00 pg/mL) to 62.4 nmol/L (18.0 ng/mL) without interference from structurally-related compounds or matrix effects. Intermediate precision was ≤3.1 % and repeatability ranged from 1.4 to 1.9 % across all analyte concentrations. The bias ranged from -1.2 to 3.0 % for all levels and matrices. Expanded measurement uncertainties (k=2) for single measurements (n=1) ranged from 3.4 to 6.4 %. Measurement uncertainties for target value assignment (n=6) were ≤1.5 %, with expanded uncertainties ≤2.9 % (k=2) for all levels. Specific assessment at the LLMI yielded an expanded uncertainty (k=2) of 4.4 % for target value assignments (n=6), confirming the method's suitability for accurate and precise quantification over the entire measuring range.
    CONCLUSIONS: The RMP demonstrated high analytical performance for testosterone quantification in human serum and plasma, making it suitable for routine assay standardization and clinical sample evaluation.
    Keywords:  SI units; isotope dilution-liquid chromatography-tandem mass spectrometry; reference material; reference measurement procedure; testosterone; traceability
    DOI:  https://doi.org/10.1515/cclm-2024-1266
  3. J Pharm Biomed Anal. 2026 Feb 13. pii: S0731-7085(26)00060-9. [Epub ahead of print]274 117392
    Development and validation of a robust UPLC-MS/MS method for the analysis of polyamines in cells, biofluids and tissues.
    Michele Iannone, Liesbeth Vereyken, Elien Grajchen, Celine Deneubourg, Sara Gorremans, Luc Ver Donck, Alexis Bretteville, Diederik Moechars, Farid Jahouh, Rob J Vreeken.
      Loss of function (LoF) of the ATP13A2 protein, a polyamines transporter, has been linked to lysosomal and mitochondrial dysfunctions that play an important role in the early onset of Parkinson's disease (PD) and related neurodegenerative disorders. To investigate the downstream consequences of these LoFs in relevant in-vitro and in-vivo models, we describe the development, optimization, validation and application of an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the quantification of a range of endogenous polyamines (putrescine, cadaverine, ornithine, spermidine, spermine, N1 acetylputrescine, N1 acetylcadaverine, N1 acetylspermidine, N1N8 diacetylspermidine and N1 acetylspermine) in cells, biofluids and brain tissues. Sample pre-treatment consists of protein precipitation, derivatization with benzoyl chloride (BZ) and liquid-liquid extraction clean-up with ethyl acetate. The chromatographic separation is achieved on an ACQUITY BEH C18 column within 5.5 min using an acetonitrile/water + 0.1 % formic acid gradient, while the mass spectrometric analysis is performed using a triple quadrupole operating in selected reaction monitoring (SRM) mode. The analytical method is validated in terms of linear dynamic range, lower and upper limit of quantification (LLOQ and ULOQ), accuracy, precision, matrix effect, carry-over and stability. LLOQ values are between 0.05 and 0.5 ng/mL while the ULOQ values are between 1*103 and 5*104 ng/mL, depending on the analyte and on the matrix. For certain compounds, the linear dynamic range extension, up to four orders of magnitude, is achieved using isotopologue transitions. Accuracy is between 97.5 % and 108.2 % while intra-day and inter-day precision, expressed as cv% of the control samples at three different concentration levels, are below 15 %. No carry-over and matrix effect are observed. The analysis of cell lysates, different biofluids (mouse plasma and mouse cerebrospinal fluid) and mouse brain tissue homogenates confirm the applicability of the developed method for the quantification of the polyamines included in the method.
    Keywords:  ATP13A2; Biological matrix; Polyamines; Quantification; UPLC-MS/MS
    DOI:  https://doi.org/10.1016/j.jpba.2026.117392
  4. J Am Soc Mass Spectrom. 2026 Feb 17.
    An Open-Source Platform for Reference Data-Driven Analysis of Untargeted Metabolomics.
    Alejandro Mendoza Cantu, Julia M Gauglitz, Wout Bittremieux.
      Untargeted tandem mass spectrometry (MS/MS)-based metabolomics enable broad characterization of small molecules in complex samples, yet the majority of spectra in a typical experiment remain unannotated, limiting biological interpretation. Reference data-driven (RDD) metabolomics addresses this gap by contextualizing spectra through comparison to curated, metadata-annotated reference data sets, allowing inference of spectrum origins without requiring exact structural identification. Here, we present an open-source RDD metabolomics platform comprising a user-friendly web application and a Python software package that performs RDD analyses directly from molecular networking outputs generated by GNPS. The tools support visualization and statistical analysis of RDD results, including interactive bar plots, heat maps, principal component analysis, and Sankey diagrams. We illustrate the approach using a hierarchical reference data set of 3500 food items to derive dietary patterns from stool metabolomics data of omnivore and vegan participants. The analysis reveals clear dietary group separation, demonstrating how RDD metabolomics can extract biologically meaningful patterns from otherwise unannotated spectra. Thus, the RDD metabolomics platform removes technical barriers for the metabolomics community to adopting RDD analysis, with the functionality freely available at https://github.com/bittremieuxlab/gnps-rdd and https://gnps-rdd.bittremieuxlab.org/.
    Keywords:  dietary read-out; reference data-driven analysis; software package; untargeted metabolomics; web platform
    DOI:  https://doi.org/10.1021/jasms.5c00372
  5. Curr Protoc. 2026 Feb;6(2): e70322
    PNA-HPLC and Hybrid LC-MS/MS as Complementary Platforms for Bioanalysis of Next-Generation Nucleic Acid Therapeutics.
    Christian Heinlein, Soham Mandal, Thessa Jacob, Steve Paulus, Lukas Sauermann, Markus Schuster, Timo Schierling, Satish Chavre, Ingo Roehl.
      Nucleic acid therapeutics (NATs), including antisense oligonucleotides and small interfering RNAs, represent an expanding class of therapeutic modalities with distinctive physicochemical, pharmacokinetic, pharmacodynamic, and biodistribution properties. Naturally, their bioanalysis requires platforms that can accurately quantify intact analytes of interest and metabolites across diverse biological matrices. Modifications ranging from 2'-modifications, alterations of the phosphate backbones, and varied ligands conjugated for targeted delivery, influence extraction recovery, matrix effects, and assay selectivity and sensitivity. Historically, ligand-binding assays and PCR-based methods were adopted due to exceptional sensitivity. However, these approaches often lacked structural resolution and overestimated intact analyte when "sequence-similar" metabolites prevailed. Conversely, two complementary methods emerged, providing higher structural resolution, i.e., peptide-nucleic acid (PNA)-based hybridization in conjunction with anion exchange high-performance liquid chromatography (PNA-HPLC assay), and liquid chromatography-tandem mass spectrometry (LC-MS/MS), enabling separation of "sequence-similar" metabolites from the parent, and additionally, metabolite identification by LC-MS and LC-MS/MS. Recent methodological advances in LC-MS/MS workflows combining sequence-specific enrichment have substantially bridged the previously observed sensitivity gap. The introduction of high-affinity capture probes has improved assay robustness and recovery for challenging analytes and enhanced signal response while minimizing matrix-effect and ion suppression. Comparative evaluation demonstrates that both the PNA-HPLC and the hybrid LC-MS/MS assays are comparably superior for metabolite profiling and tissue distribution studies. This article integrates the analytical principles, strengths, and limitations of those two assays with exemplary case studies for NATs. Practical guidance is provided for method selection, probe selection, sample preparation, assay validation, and cross-platform harmonization. Emerging trends include PNA probe engineering and high-resolution MS for structural elucidation. The integration of capture probe-based hybridization enrichment with modern LC-MS/MS detection now enables combined sensitivity and specificity. Together, these developments support increasingly robust, convergent, regulatory-compliant bioanalytical strategies for next-generation oligonucleotide therapeutics. © 2026 Wiley Periodicals LLC. Basic Protocol 1: PNA hybridization-based HPLC assay for the detection and quantification of therapeutic oligonucleotide in biological tissue samples Basic Protocol 2: Hybrid LC-MS/MS quantitative assay for identification and evaluation of NAT in biological tissue samples.
    Keywords:  LC–MS/MS assays; low “lower limit of quantification” (LLOQ); method validation and metabolite profiling; oligonucleotide bioanalysis; peptide nucleic acid (PNA)‐HPLC assay
    DOI:  https://doi.org/10.1002/cpz1.70322
  6. Methods Enzymol. 2026 ;pii: S0076-6879(25)00486-0. [Epub ahead of print]726 85-104
    Alkyne lipids as tracers of lipid metabolism.
    Christoph Thiele.
      The high complexity of cellular lipidomes and of the underlying metabolic pathways requires powerful labeling and detection systems for systematic lipid tracing experiments. Alkyne fatty acids are tracers with favorable biological properties very similar to unlabeled natural counterparts. We have developed a labeling and detection system based on alkyne lipid tracers and specialized reporter molecules that confer high specificity and sensitivity to labeled metabolites. Tracers are added to living cells and metabolites are extracted in pulse-chase setups to achieve time resolution. Copper(I)-dependent click reaction between extracted lipids and the C171 or C175 reporter molecules is followed by mass spectrometry analysis. The reporter carries a positive charge leading to improved ionization and increased sensitivity. Uniform and predictable neutral loss-type fragmentation in tandem mass spectrometry leads to reliable identification and quantification of labeled metabolites. Parallel multi-labeling with several precursors, combined with multiplexed analysis enables efficient high-content tracing. This chapter introduces the basic concepts and a step-by-step protocol with detailed explanation of key procedures to obtain optimal results.
    Keywords:  Click reaction; Lipid metabolism; Mass spectrometry; Reporter molecule
    DOI:  https://doi.org/10.1016/bs.mie.2025.11.005
  7. J Proteome Res. 2026 Feb 18.
    Scalable Incremental Clustering for Tandem Mass Spectra in Untargeted Metabolomics.
    Xianghu Wang, Deepa D Archarya, Christopher J Brown, Ken Clevenger, Jie Hu, Ashley Kretsch, Carla Menegatti, Quanbo Xiong, Wout Bittremieux, Mingxun Wang.
      Tandem mass spectrometry (MS/MS) has become the analytical backbone of large-scale untargeted metabolomics, routinely generating millions of spectra per study. However, existing clustering methods struggle to process this scale due to computational and memory bottlenecks, limiting the utility of clustering in downstream analysis. This bottleneck is especially acute in long-term studies and public repositories, where new data are continuously added over time. Here we present a scalable clustering framework for MS/MS metabolomics data. Our method incrementally incorporates new spectra batches while preserving clustering performance through a novel spectrum pooling strategy, which propagates local density structure across batches. Using both database-search-based evaluation on proteomics data sets and the MS1-retention time (MS-RT) method on metabolomics data sets, we show that incremental clustering achieves comparable performance to the state-of-the-art clustering methods in terms of cluster purity and completeness. Critically, our approach scales up to clustering tasks consisting of 368 million spectra clustering task and millions of clusters, completing in under 10,000 CPU hours, while traditional methods could not scale to this data volume and failed to complete due to excessive memory or time requirements. Our method offers a practical solution for large-scale, continuously growing MS/MS studies and is well suited for integration into public metabolomics platforms such as GNPS2.
    Keywords:  MS-RT evaluation; falcon; incremental clustering; large-scale clustering; metabolomics; spectrum pooling; tandem mass spectrometry
    DOI:  https://doi.org/10.1021/acs.jproteome.5c00998
  8. Chemosphere. 2026 Mar;pii: S0045-6535(26)00040-8. [Epub ahead of print]396 144863
    A clean-up method to remove taurine conjugated bile acid isomers interference for perfluorooctane sulfonate (PFOS) analysis in biotic matrices by isotope dilution LC-MS/MS and investigation of other MRMs interference.
    Chunhai Yu, Gavin Stevenson, Robert Crough, Jesuina De Araujo, Alan Yates.
      This paper presents a clean-up method to remove the Multiple Reaction Monitoring (MRM) isobaric interference from taurine conjugated bile acid isomers to the primary transition ion m/z = 499 > 80 for PFOS analysis in biological samples. Upon the identification of taurodeoxycholate (TDCA) isomers interference, the sample was evaporated to dryness under nitrogen, reconstituted with 1% formic acid in acetonitrile, then passed through an Agilent EMR-lip Solid-Phase-Extraction (SPE) cartridge. The eluent was concentrated and re-analysed. The method has been successfully applied in PFOS analysis of serum, liver, egg, shrimp, and fish samples with comparable values between two transition ions m/z = 499 > 80 & 99 and spike recoveries from 70% to 125%. Another interference to m/z = 499 > 80 in shrimp samples was investigated and tentatively speculated as taurine conjugate with unsaturated fatty acid. In addition, the method could remove the steroid sulfates interference to PFHxS transitions m/z = 399 > 80 and m/z = 399 > 99 in human serum samples. The Perfluoro-1-methylheptanesulfonate (P1MHpS), a branched PFOS isomer (br-PFOS), was identified to interfere with PFOS quantification in serum samples, causing either over- or under-estimation of PFOS values due to its response factors being 250% for the m/z = 499 > 99 transition and 5% for 499 > 80 transition. A calculation formula was proposed for quantification of P1MHpS and total PFOS values. About 20% of serum samples contained significant P1MHpS at 12-27% of total PFOS, indicating its high accumulation behaviour in human serum.
    Keywords:  LC-MS/MS; MRM isobaric interference; P1MHpS; PFOS; TDCAs; Taurine conjugates
    DOI:  https://doi.org/10.1016/j.chemosphere.2026.144863
  9. Biomed Chromatogr. 2026 Apr;40(4): e70386
    Advances in Analytical Strategies for Precise Quantification of Topoisomerase Inhibitors: Current Trends and Future Directions.
    Hoshyar Saadi Ali, Hemn A H Barzani, Rebaz Anwar Omer, Khalamala Ibrahim Salih Barzani, Seerwan Hamadameen Sulaiman, Musher Ismael Salih, Aryan Fathulla Qader.
      Topoisomerase inhibitors (TIs) are a cornerstone class of anticancer and antimicrobial agents, yet their accurate quantification in pharmaceutical formulations and biological matrices remains analytically challenging. These difficulties stem from marked structural diversity, poor aqueous solubility, narrow therapeutic windows, very low circulating concentrations, chemical instability, and, for camptothecin derivatives, pH-dependent interconversion between active lactone and inactive carboxylate forms. This review critically evaluates current analytical approaches for determining widely used TIs, including topotecan, irinotecan, etoposide, epirubicin, dexrazoxane, and camptothecin, with emphasis on selectivity, sensitivity, applicability, and robustness in complex matrices. Conventional spectroscopic methods and HPLC with UV or fluorescence detection remain useful for formulation analysis and preliminary screening but often lack sufficient selectivity and sensitivity for biological samples. Electrochemical techniques, especially those employing nanomaterials or molecular recognition elements, offer high sensitivity and low sample consumption; however, their routine application is limited by matrix effects and scarce regulatory validation. In contrast, ultrahigh-performance liquid chromatography coupled with tandem or high-resolution mass spectrometry (UHPLC-MS/MS or UHPLC-HRMS) provides superior selectivity, sub-ng mL-1 sensitivity, and reliable discrimination of parent drugs and metabolites across diverse matrices. Overall, UHPLC-MS-based methods emerge as the current gold standard for TI quantification, supporting clinical, pharmacokinetic, and regulatory applications in modern analytical science.
    Keywords:  camptothecin; chromatographic; etoposide; irinotecan; topoisomerase; topotecan
    DOI:  https://doi.org/10.1002/bmc.70386
  10. Methods Enzymol. 2026 ;pii: S0076-6879(25)00530-0. [Epub ahead of print]726 193-215
    Visualization of single-cell lipidomes with MALDI-MSI.
    Jean Andrea Maillat, Nika Goršek, Pavel Barahtjan, Giovanni D'Angelo.
      Lipids are central to cellular structure, metabolism, and signaling, and yet their distribution within and across cells is highly heterogeneous. Traditional bulk mass spectrometry masks this diversity, whereas single-cell lipidomics can uncover distinct lipid configurations that define cellular states and organize tissues. Matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) has emerged as a powerful tool to probe lipid heterogeneity beyond bulk analyses. Here, we describe a workflow for single-cell lipidomics that integrates optimized matrix deposition, high-resolution acquisition, and optical co-registration. This approach enables label-free, spatially resolved detection of endogenous lipid species with cellular precision and minimal sample perturbation. Applied to cultured cells, the method uncovers pronounced cell-to-cell variability and reveals coherent lipid domains across neighboring cells in tissues. By providing a robust and scalable strategy for visualizing lipidomes at single-cell resolution, MALDI-MSI bridges the gap between lipid localization and metabolic diversity, advancing lipidomics toward the study of cellular identity, tissue organization, and disease mechanisms.
    Keywords:  MALDI-MSI; lipid heterogeneity; single-cell lipidomics; spatial metabolomics
    DOI:  https://doi.org/10.1016/bs.mie.2025.12.003
  11. J Am Soc Mass Spectrom. 2026 Feb 18.
    Profiling of Low-Abundance Branched-Chain Fatty Acids via Radical Directed Dissociation Tandem Mass Spectrometry.
    Ruijun Jian, Shengzhuo Wang, Lipeng Qiao, Xue Zhao, Yu Xia.
      Branched-chain fatty acids (BCFAs) are key components of the bacterial lipidome, playing a role in regulating membrane fluidity and permeability. In mammals, BCFAs occur at much lower concentrations, and their functions remain largely unexplored. Conventional lipid analysis methods, employing collision-induced dissociation (CID)-tandem mass spectrometry (MS/MS), often fail to locate methyl branching, as fragmentation rarely occurs around the branching site. Here, we introduce a bifunctional derivatization reagent, 1-(8-methoxy-5-quinolinyl) methanamine (MeO-QN), for pinpointing methyl branching in BCFAs with high sensitivity. MeO-QN enhances ionization efficiency of derivatized BCFAs in positive ion mode due to its quinoline moiety and serves as a precursor for radical-directed dissociation (RDD). Upon CID, the quinoline-O radical (QN-O•) is generated, which subsequently induces RDD along the fatty acyl chain and forms a characteristic 28 Da spacing indicative of the branching point. By integrating this MS/MS method with reversed-phase liquid chromatography, we have developed a sensitive analytical workflow, detecting BCFAs at sub-nM levels in mammalian samples. We detected the rarely reported n-5 methyl branched fatty acid (FA 16:0;12Me) in pooled human plasma. We also observed significantly reduced even-chain isobranched fatty acids in breast cancer cells (MDA-MB-468) versus normal breast cells (MCF-10A), suggesting its potential in cancer biomarker discovery.
    Keywords:  branched-chain fatty acids; liquid chromatography; quinoline-O radical; radical-directed dissociation; tandem mass spectrometry
    DOI:  https://doi.org/10.1021/jasms.6c00001
  12. Front Pharmacol. 2026 ;17 1731595
    Development of an LC-MS/MS method for amantadine detection in human plasma using ZIF-8 as adsorbent and pharmacokinetic investigation.
    Zhengang Wang, Huanmei Han, Hongxia Li, Wenjuan Xu, Kuiying Ding.
      In this study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantitative determination of amantadine in human plasma, with the incorporation of an internal standard to improve analytical accuracy. Plasma samples collected from volunteers were processed using acetonitrile-methanol (3:1, v/v) as the extraction solvent, followed by protein precipitation and purification via the QuEChERS (Quick, Easy, Cheap, Efficacious, Rugged, and Safe) method. Analysis was performed using LC-MS/MS under multiple reaction monitoring mode, with a total run time of 8 min. Quantification was carried out using the internal standard method. After a single oral administration of 200 mg amantadine hydrochloride, plasma concentrations were measured at various time points. Pharmacokinetic parameters were derived by fitting the data to a pharmacokinetic model using specialized software. The results demonstrated good linearity over the range of 0.5-20 ng/mL, with a correlation coefficient (R2) of 0.9978. The extraction recovery ranged from 94.5% to 110.1%, and both intra-day and inter-day relative standard deviations (RSD) were below 10%. The limit of detection (LOD) and limit of quantification (LOQ) were 0.15 ng/mL and 0.5 ng/mL, respectively. The absorption and elimination processes of amantadine in plasma followed first-order kinetics, with R2 > 0.9. Notably, gender-specific differences were observed in the time to maximum concentration (Tmax) and maximum concentration (Cmax): females achieved a Cmax of 670.23 ng/mL at 4 h, whereas males reached a Cmax of 650.87 ng/mL at 8 h. This LC-MS/MS method is simple, rapid, and accurate, rendering it suitable for pharmacokinetic studies of amantadine in humans. Additionally, the established kinetic model provides valuable references for clinical medication guidance.
    Keywords:  LC-MS/MS; amantadine; human plasma; pharmacokinetics; therapeutic drug monitoring
    DOI:  https://doi.org/10.3389/fphar.2026.1731595
  13. Methods Enzymol. 2026 ;pii: S0076-6879(25)00489-6. [Epub ahead of print]726 157-180
    High-resolution sphingolipid analysis in vitro using LC-qToF MS.
    Shweta Chitkara, G Ekin Atilla-Gokcumen.
      The complexity of the sphingolipidome, characterized by variations in chain length, saturation, and headgroup composition, makes it essential to develop analytical strategies capable of high sensitivity and structural precision. Traditional biochemical methods lack the resolution to discriminate among closely related species, underscoring the transformative role of liquid chromatography-mass spectrometry (LC-MS) in sphingolipidomics. LC-MS provides unparalleled capabilities for sphingolipid analysis, combining chromatographic separation with high-resolution mass detection to achieve both qualitative and quantitative accuracy. In particular, liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC-qToF MS) has emerged as a powerful platform, offering mass accuracy, broad dynamic range, and rapid acquisition rates. These features enable confident identification of isobaric and structurally related sphingolipids, which is essential for understanding their roles in cellular physiology and pathology. This chapter focuses on an optimized LC-qToF MS method tailored for sphingolipid profiling in cultured mammalian cells. By focusing on the analytical strengths of LC-MS, the approach provides a robust foundation for dissecting sphingolipid metabolism and its dysregulation in cellular processes.
    Keywords:  Ceramides; LC-MS; LC-qToF MS; Sphingolipids
    DOI:  https://doi.org/10.1016/bs.mie.2025.11.008
  14. Anal Chem. 2026 Feb 19.
    Trifluoromethylphenyl-Induced Specific Acyl Chain Fragmentation in Liquid Chromatography Mass Spectrometry for Free Furan Fatty Acid Screening in Fish Oils.
    Xiao-Hui Peng, Jian-Li Chen, Dan Luo, Hua-Ming Xiao, Yu-Qi Feng.
      Furan fatty acids (FuFAs) are special minor dietary lipids characterized by a furan ring structure, widely present in food sources, such as fish and plant oils. They exhibit potent antioxidant and anti-inflammatory activities, along with potential benefits for cardiovascular and metabolic health, with evidence suggesting that their physiological significance may surpass that of omega-3 fatty acids. However, the development of reliable methods for screening and structural elucidation of FuFAs in complex matrices has been hindered by the limited availability of chemical standards and their inherent photosensitivity. Herein, we propose a nontargeted liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS)-based method for the detection of free FuFAs using a trifluoromethyl-substituted phenyl bromoacetamide derivatization strategy. This labeling approach induces specific fragmentation during MS/MS analysis, generating diagnostic fragment ions derived from the furan moiety. Through comprehensive evaluation of various carboxylic acid derivatization reagents, including comparing retention behavior, isotopic patterns, fragmentation profiles, analytical performance in real samples, and theoretical calculations, the proposed method based on specific MS/MS fragmentation patterns was demonstrated to enable direct determination of FuFAs in complex lipid matrices, such as fish and plant oils. Furthermore, it facilitates the preliminary identification of key structural features of FuFAs, including the number of double bonds and substituent positions, and allows for structural assignment with minimal reliance on reference standards. This approach provides a straightforward, efficient, and data-simplified strategy for the structural identification of FuFAs in complex matrices.
    DOI:  https://doi.org/10.1021/acs.analchem.5c07753
  15. Anal Bioanal Chem. 2026 Feb 16.
    Reliable LC-MS/MS method integrated with a linear retention index approach for multiresidue pesticide analysis in hemp seed oil.
    Antonio Ferracane, Roberto Laganà Vinci, Francesca Rigano, Katia Arena, Michal Kašpar, Inmaculada Moscoso-Ruiz, Petr Česla, Francesco Cacciola, Paola Dugo, Luigi Mondello.
      The increasing global demand for hemp seed oil (HSO) necessitates robust analytical methods to monitor pesticide residues and ensure compliance with increasingly stringent international regulations. This study presents a rapid and efficient multiresidue method for the determination of 148 pesticides in HSO using liquid chromatography-tandem mass spectrometry (LC-MS/MS), coupled with a linear retention index (LRI) approach to enhance compound identification confidence. The method features a streamlined extraction protocol with reduced solvent consumption (5 mL ACN per sample) and achieves chromatographic separation within 12 min. Method validation demonstrated excellent sensitivity (LOQs, 0.03-22.29 ng g⁻1), accuracy (71-129%), and precision (RSD ≤ 19.9%). Integration of the LRI system enabled unambiguous differentiation of isomeric compounds. Application of the method to 12 commercial HSO samples revealed the presence of 21 pesticides, with malathion and proquinazid exceeding Canadian maximum residue limits (MRLs) in two samples. This robust and eco-efficient method provides a robust solution for pesticide monitoring in HSO, aligning with EU, Canadian, and Californian regulatory frameworks while introducing LRI as a valuable tool for pesticide analysis in complex lipid matrices.
    Keywords:  Hemp seed oil; Linear retention index; Liquid chromatography; Multiresidue analysis; Pesticides; Tandem mass spectrometry
    DOI:  https://doi.org/10.1007/s00216-026-06388-3
  16. J Proteome Res. 2026 Feb 15.
    MetaboliteAnnotator: AI-Assisted Name Harmonization and Metadata Enrichment Tool for Metabolomics.
    Zhong-Hua Lu, Chen Tang, Rui Guo, Hao Chang, Yan-Ru Xu, Jie Zhang.
      Metabolite metadata enrichment remains a significant challenge in metabolomics due to the limitations of static databases, incomplete metabolite coverage, and the labor-intensive nature of manual verification. Here, we present MetaboliteAnnotator, an R Shiny-based application for AI-assisted metabolite name harmonization and metadata enrichment. MetaboliteAnnotator implements a hierarchical procedure, including preprocessing of input metabolite names, matching against a curated local resource (covering information on ∼640,000 metabolites names), PubChem-based real-time retrieval, and AI-assisted matching for ambiguous compounds, followed by real-time integration of KEGG, CTD, Reactome, and ChEBI. Compared with MetaboAnalyst 6.0 and MetaboliteIDmapping, MetaboliteAnnotator achieved significantly higher name hit rates across all six MetaboLights data sets 93.2% in positive mode (4021/4314 names) and 93.5% in negative mode (2344/2510 names). MetaboliteAnnotator outputs standardized identifiers (e.g., InChIKey, PubChem CID), endogenous/exogenous information, pathway mappings, and metabolite-gene/phenotype associations for downstream biological interpretation.
    Keywords:  data integration; generative artificial intelligence; metabolite metadata; metabolomics; name harmonization
    DOI:  https://doi.org/10.1021/acs.jproteome.5c00477
  17. Food Chem. 2026 Feb 16. pii: S0308-8146(26)00605-9. [Epub ahead of print]508(Pt B): 148447
    Coupling micro-flow liquid chromatography with Q-Orbitrap high-resolution mass spectrometry for greener, comprehensive pesticide residue analysis in fruits and vegetables.
    Florencia Jesús, Francisco José Díaz-Galiano, Amadeo Rodríguez Fernández-Alba.
      A micro-flow liquid chromatography coupled with Q-Orbitrap high-resolution mass spectrometry (micro-flow LC-HRMS) method was developed for multiresidue pesticide analysis in fruits and vegetables. The data acquisition workflow integrated full scan, variable data-independent acquisition and data-dependent MS2 experiments. Using a 0.3 mm internal diameter column at 15 μL·min-1, the micro-flow LC configuration enhanced ionisation efficiency and improved sensitivity, achieving instrumental limits of quantification at or below 0.010 mg·kg-1 for 239 pesticides in tomato, orange and avocado. The method showed excellent retention time and peak area stability, broad linearity, and low matrix effects for most compounds. Proficiency tests and real sample results confirmed its accuracy and suitability for routine monitoring. Micro-flow LC-HRMS provides a robust, sensitive and information-rich platform for pesticide residue monitoring in food, enabling comprehensive targeted quantification and non-targeted data collection within a single run. This greener approach reduces solvent consumption and waste by 25-fold compared with classical LC solutions.
    Keywords:  Food safety; Miniaturized liquid chromatography; ddMS(2); vDIA
    DOI:  https://doi.org/10.1016/j.foodchem.2026.148447
  18. J Chromatogr A. 2026 Feb 11. pii: S0021-9673(26)00128-7. [Epub ahead of print]1773 466798
    Advances in LC-MS/MS methods and sample preparation strategies for therapeutic drug monitoring of immunosuppressive drugs.
    Selen Al, Demet Dincel, Aykut Kul, Olcay Sagirli.
      Immunosuppressive drugs play a critical role in preventing organ rejection following transplantation and require close monitoring due to their narrow therapeutic ranges and interindividual pharmacokinetic variability. This review provides an overview of the pharmacokinetic properties, mechanisms of action, and clinical applications of drugs such as cyclosporine A, tacrolimus, sirolimus, everolimus, mycophenolate mofetil, and azathioprine. Within this clinical context, therapeutic drug monitoring (TDM) represents a cornerstone of individualized immunosuppressive therapy, directly linking drug exposure to efficacy and safety outcomes. Analytical approaches commonly used in the therapeutic monitoring of these agents-high-performance liquid chromatography (HPLC), liquid chromatography-tandem mass spectrometry (LC-MS/MS)-are described, with particular emphasis on LC-MS/MS as the primary analytical platform due to its superior selectivity, sensitivity, and multi-analyte capability. Recent advancements in sample preparation techniques are discussed in relation to their role in minimizing matrix effects and meeting the stringent analytical requirements of TDM. Tabulated data are presented on instrumentation, sample matrices, sample preparation techniques, calibration ranges, lower limits of quantification (LLOQ), analysis times, mobile phase compositions, and chromatographic columns for each analytical method. By critically integrating analytical methodology with clinical TDM needs, this review is intended to provide researchers and clinicians with a useful reference that supports the advancement of more effective and dependable strategies for therapeutic drug monitoring in clinical settings.
    Keywords:  Analytical methods; Immunosuppressive drugs; LC-MS/MS; Sample preparation; Therapeutic drug monitoring
    DOI:  https://doi.org/10.1016/j.chroma.2026.466798
  19. Methods Enzymol. 2026 ;pii: S0076-6879(25)00484-7. [Epub ahead of print]726 333-355
    Mass spectrometry-based lipid analysis in NPC1 disease: Methods for phosphoinositide quantification, lipid imaging, and myelin lipid profiling.
    Koralege C Pathmasiri, Stephanie M Cologna.
      Loss of NPC cholesterol transporter 1 protein function results in severe lipid dysregulation in multiple vital organs, including the brain, in Niemann-Pick Type C1 (NPC1) disease. Investigation of lipid changes and lipid metabolism disruptions in NPC1 is critical to elucidating the disease mechanisms driving the pathophysiology, identifying potential biomarkers, and guiding therapeutic strategies. One such example is phosphoinositides, which are key lipids involved in multiple signaling pathways relevant to NPC1 that are challenging to study due to their low abundance and detection difficulty. In this chapter, we present a detailed phosphoinositide analysis protocol using mass spectrometry. When studying lipids, spatial information is also important because it reveals distribution within the tissue, which can provide insights into functional roles and disease-related alterations. MALDI-MS lipid imaging is a powerful tool for investigating the spatial distribution of lipids. Herein, we also discuss a protocol for lipid imaging using MALDI-MSI, along with key precautions and troubleshooting tips. Finally, we present a myelin isolation protocol integrated with LC-MS lipidomics to investigate the myelin lipidome in tissues such as the brain, as myelin lipid composition is crucial for maintaining neuronal function and is often disrupted in neurodegenerative diseases like NPC1, including the investigation of phosphoinositides.
    Keywords:  Chromatography; Imaging; Lipidomics; Mass spectrometry; Niemann-Pick Type C
    DOI:  https://doi.org/10.1016/bs.mie.2025.11.003
  20. Talanta. 2026 Feb 09. pii: S0039-9140(26)00180-3. [Epub ahead of print]304 129525
    Supercritical fluid chromatography hyphenated with dielectric barrier discharge ionization mass spectrometry: A universal approach to analysis of complex plant extracts.
    Kateřina Plachká, Karel Vraj, Veronika Pilařová, Lucie Nováková.
      The chemical diversity of plant secondary metabolites, ranging from volatile nonpolar terpenes to polar flavonoid glycosides, often necessitates the combined use of gas chromatography and liquid chromatography for comprehensive profiling. In this study, we present a universal analytical platform based on supercritical fluid chromatography coupled with mass spectrometry (SFC-MS) that enables broad-spectrum analysis of plant extracts in a single run. A novel SFC method was developed employing a pentabromobenzyl stationary phase and a CO2-based mobile phase modified with 3 mmol/L ammonium fluoride in methanol. Separation of 62 diverse phytochemicals, including terpenes, vitamins, phenolic acids, and flavonoids, was achieved within 12 min. To address the ionization challenges posed by this chemically heterogeneous analyte panel, we evaluated both a dual ionization source combining electrospray and atmospheric pressure chemical ionization and an alternative commercially available soft ionization technique, which utilizes dielectric barrier discharge in cold plasma. This source demonstrated effective ionization of different chemical structures, enabling the detection of both functionalized polar compounds and nonfunctionalized terpenes in a single ionization mode. The method applicability was evaluated by analyzing five different plant extracts, highlighting its potential as a truly universal tool for phytochemical analysis.
    Keywords:  Dielectric barrier discharge ionization; Flavonoids; Ionization source; Plant extract; Supercritical fluid chromatography; Terpenes
    DOI:  https://doi.org/10.1016/j.talanta.2026.129525
  21. J Chromatogr A. 2026 Jan 06. pii: S0021-9673(26)00007-5. [Epub ahead of print]1773 466676
    Novel spectral comparison for chlorinated paraffin analysis using planar solid phase extraction coupled to high-resolution mass spectrometry.
    Sandra Geyer, Panagiotis Steliopoulos, Jana Leber, Gertrud E Morlock, Claudia Oellig.
      Separation of chlorinated paraffins (CP) from complex matrices is challenging and their accurate quantification lacks in reference substances. A reference standard-free approach was newly applied to combine planar solid phase extraction (pSPE), high-resolution mass spectrometry (HRMS), and a mathematical comparison between computed and observed isotopic patterns for the objective, data-driven evaluation of the CP composition. The dopant ammonium chloride enabled the sensitive and reproducible detection and assignment of CP congeners. This was demonstrated for two technical CP standard mixtures, in which 31 and 28 congeners were assigned with high consistency by flow injection analysis-ESI-HRMS and pSPE-ESI-HRMS, respectively. In spiked vegetable oils, the expected congener pattern was successfully recovered, confirming the applicability of pSPE-ESI-HRMS for complex sample analyses. Applicability to real samples was demonstrated for CP congeners detected in CP-contaminated vegetable oils. The differentiation between explainable and unexplained mass spectrometric signals provided an optional non-target analysis. To ensure reproducibility and transparency, an evaluation routine based on a mathematically defined spectral similarity score was implemented, allowing a clear criterion for congener assignment. For future quantification, hexabromocyclododecane was evaluated as a suitable internal standard. The developed method enables an objective, reproducible, and accreditation-oriented approach suitable for automated evaluation for CP assignment without reference standards.
    Keywords:  Chlorinated paraffins; Planar solid phase extraction – high-resolution mass spectrometry (pSPE–HRMS); Reference standard-free assignment; Spectral similarity score
    DOI:  https://doi.org/10.1016/j.chroma.2026.466676
  22. Methods Enzymol. 2026 ;pii: S0076-6879(25)00488-4. [Epub ahead of print]726 357-378
    Multi-structural profiling of neutral glycosphingolipids using selective enrichment and the Paternò-Büchi derivatization.
    Zidan Wang, Yichun Wang, Yu Xia.
      Neutral glycosphingolipids (GSLs) are important glycan scaffolds in mammal cell membranes, typically comprising one to four neutral monosaccharide units. They also serve as precursors for the biosynthesis of more complex acidic GSLs. Accumulating evidence links alterations in neutral GSL profiles to various physiological and pathological processes. However, the detailed structural characterization of GSL remains challenging owing to their low abundance and structural complexity. Herein, we present a deep profiling workflow for neutral GSLs which combines a selective enrichment strategy using magnetic titanium dioxide nanoparticles with off-line charge-tagging Paternò-Büchi derivatization and liquid chromatography-mass spectrometry analysis. This approach provides unique characterization capability on multiple-structural levels, including headgroup identity, chain composition, carbon-carbon double bond location, and hydroxylation site. This workflow allows deep profiling over 300 structural of neutral GSLs, with relative concentrations across three orders of magnitude from porcine brain total lipid extracts, human brain tissue, and human plasma.
    Keywords:  Magnetic titanium dioxide nanoparticle; Mass spectrometry; Neutral glycosphingolipid; Paternò–Büchi reaction; Structural characterization
    DOI:  https://doi.org/10.1016/bs.mie.2025.11.007
  23. J Anal Toxicol. 2026 Feb 15. pii: bkag013. [Epub ahead of print]
    GC-FID Quantification of Methanol, Ethanol, 2-Propanol, Acetone, Ethylene Glycol, Diethylene Glycol, 1,2-Propylene Glycol and 1,3-Propylene Glycol in Plasma.
    Mohsin El Amrani, Arjan Zandbergen, Mike Groot, Tim Bognar, Erin H Smeijsters, Kim C M van der Elst.
      Alcohol and glycol ingestion, including substances such as methanol, ethylene glycol, and isopropanol, constitutes a serious medical emergency that requires prompt diagnosis and treatment of patients. Rapid and accurate quantification of these compounds in plasma is essential to guide clinical decision-making and prevent delays in treatment that could result in irreversible organ damage or death. Many healthcare facilities lack analytical methods capable of simultaneously quantifying both alcohols and glycols in a single run. This study describes the development and validation of a rapid gas chromatography-flame ionization detection (GC-FID) method for the simultaneous screening and quantification of methanol, ethanol, 2-propanol, acetone, ethylene glycol, diethylene glycol, 1,2-propylene glycol and 1,3-propylene glycol in human plasma. Plasma samples were prepared using a protein precipitation technique with acetonitrile containing two internal standards: 2-butanol and 1,4-butanediol. Acetonitrile effectively precipitated plasma proteins. The supernatant was then subjected to GC-FID analysis for quantification of the target alcohols and glycols. The total analytical run time was 5 minutes, enabling the quantification of eight analytes in a single injection. The method demonstrated excellent linearity, with correlation coefficients (R2) exceeding 0.9995 for all compounds. The linear dynamic range was 40-1280 mg/L for methanol, 2-propanol, acetone, ethylene glycol, diethylene glycol, 1,2-propylene glycol, and 1,3-propylene glycol, and 80-2560 mg/L for ethanol. Within-run and between-run precision and accuracy (CV and bias) for all analytes were within the accepted criteria of ± 15%. No significant interference, carry-over, or matrix effects were observed, confirming the method's selectivity and robustness. The developed GC-FID method enables rapid, accurate, and simultaneous quantification of toxic alcohols and glycols in plasma within a 5-minute run time. The excellent linearity, precision, and selectivity of the method met all analytical performance criteria, making it well-suited for routine clinical use. This method provides a valuable tool for timely diagnosis and management of suspected toxic alcohol and glycol ingestions in patients in emergency settings.
    Keywords:  Clinical toxicology; GC-FID; Glycols; Rapid quantification; Toxic alcohols
    DOI:  https://doi.org/10.1093/jat/bkag013
  24. Talanta. 2026 Feb 12. pii: S0039-9140(26)00196-7. [Epub ahead of print]304 129541
    Chemometrics-assisted validation of a high-throughput method for quantitative analysis of multiclass phytohormones across plant matrices by UHPLC-QQQ-MS/MS for targeted metabolomics.
    Tingting Tong, Lili He, Liya Qiao, Yaqin Zhou, Jieqiong Li, Jie Liang, Jine Fu, Shugen Wei, Gaowu Huang, Xianghua Xia.
      The quantification of phytohormones in plant samples is significantly challenging because of their trace concentrations and the complex plant matrix. This study establishes and optimizes a simple and fast method for simultaneous quantification of multiclass phytohormones using ultra high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (UHPLC-QQQ-MS) for high-throughput targeted metabolomics analysis. It is characterized by simplicity and operational feasibility, and it involves sequential steps of ultrasound-assisted extraction, centrifugation, and nitrogen flow-drying. The assessment of sample preprocessing method employs the technique for order preference by similarity to an ideal solution (TOPSIS) chemometrics-assisted approach, and methanol containing 1% formic acid was selected as the optimal extraction solvent. Quantitative analysis is performed via a multiple reaction monitoring method. The method was validated satisfactory for 31 phytohormones, the specific concentration levels used to estimate recovery and precision were 0.25-200 ng/mL, and the results showed good linearity (correlation coefficients: 0.9910-0.9999), sensitivity (LOD: 0.01-2.87 ng/g; LOQ: 0.02-8.70 ng/g), accuracy (recovery rates: 64.50-129.67%), precision (relative standard deviations <20%, except for IAA-Trp), and its applicability to a variety species of medicinal plant was verified, including Taxillus chinensis (DC.) Danser, Ophiopogon japonicus (L.f.) Ker-Gawl, Citrus grandis "Tomentosa," Plumeria rubra L. "Acutifolia," and Pogostemon cablin (Blanco) Benth. In the real samples analyzed, auxins concentrations exceeded 4.07 μg/g, salicylic acids concentrations ranged from 0.027 to 79.7 μg/g, and concentrations of other categorize of phytohormones were below 1 μg/g. The established method demonstrated high throughput, accuracy, stability, and reliability. It can be extended to cover additional phytohormone types and diverse application scenarios. This method serves as a potent tool for investigating the function of multiclass phytohormones in the regulation of secondary metabolite accumulation in medicinal plants, elucidating complex signal transduction mechanisms and interaction networks, and laying the groundwork for improving the quality of Chinese medicinal materials.
    Keywords:  Chemometrics; High-throughput; Phytohormones; Targeted metabolomics; UHPLC-QQQ-MS/MS
    DOI:  https://doi.org/10.1016/j.talanta.2026.129541
  25. Anal Chim Acta. 2026 Mar 22. pii: S0003-2670(26)00093-0. [Epub ahead of print]1392 345143
    Imaging mammalian lipids using desorption electrospray ionization mass spectrometry: A review.
    Reham Abu Ghoush, Fakhri Geday, Oz Alon, Vijaya Lakshmi Kanchustambham, Sarah E Noll, Katherine Margulis.
      Desorption electrospray ionization mass spectrometry imaging (DESI-MSI) has become an essential tool for spatial lipidomic profiling since its introduction in 2005. It provides key insights into the roles of lipids in cellular function, disease mechanisms, and therapeutic development, especially within heterogeneous tissues. Understanding lipid modifications and their spatiotemporal distribution in both healthy and diseased states is crucial, given the strong link between lipid metabolism dysregulation and numerous diseases. This review offers an overview of DESI-MS imaging of mammalian lipids, highlighting challenges and advancements in lipid quantification, identification, and sample preparation optimization. We further emphasized the integration of machine learning and statistical analyses with DESI-MSI to navigate the complexity of lipidomic data, enabling the discovery of diagnostic biomarkers and the development of personalized therapeutic strategies. Specific applications of DESI-MSI in studying lipids under physiological and pathological conditions are discussed, with an emphasis on disease diagnosis, precision medicine, and therapeutics. Additionally, we reviewed the use of lipid analysis in non-medical applications such as forensics, public safety, and cosmetics. In conclusion, this review highlights the role of DESI-MSI in lipidomics, emphasizing its current challenges and future directions. Ongoing technological progress in DESI-MSI is expanding its applications in clinical diagnostics, pharmaceutical research, and personalized medicine. With deeper integration of computational tools and multi-omics approaches, DESI-MSI is well-positioned to accelerate the discovery of novel lipid biomarkers and support the development of precise therapeutic strategies.
    Keywords:  DESI-MSI; Electrospray ionization; Lipidomics; Lipids; Machine learning; Mass spectrometry imaging; OMICS
    DOI:  https://doi.org/10.1016/j.aca.2026.345143
  26. Anal Chim Acta. 2026 Apr 01. pii: S0003-2670(26)00104-2. [Epub ahead of print]1393 345154
    RNA sample preparation strategies for mass spectrometry sequencing of the epitranscriptome and therapeutic RNAs: A review.
    Nina J Fitzgerald, Weichen Huang, Kevin D Clark.
       BACKGROUND: More than 170 post-transcriptional modifications of RNA have been discovered to date that are increasingly recognized as key contributors to all aspects of RNA function, including RNA metabolism, trafficking, and translation properties. These modifications range in complexity from simple methylations to glycosylations and altogether constitute what is known as the epitranscriptome. Chemical modifications are also strategically incorporated into RNA therapeutics to enhance RNA stability, reduce immunogenicity, and improve translational efficiency. As a result of their critical importance to the function of both endogenous and therapeutic RNAs, there is intense demand for methods that enable sequencing and quantification of RNA modifications.
    RESULTS: Here, we provide a critical review of state-of-the-art sample preparation strategies for mass spectrometry (MS)-based sequencing of RNA modifications. We offer guidance on selecting methods for extraction, purification, preconcentration, and RNA labeling that are tailor-made for specific sample matrices and RNA types.
    SIGNIFICANCE: Mass spectrometry has emerged as an indispensable technique for sequencing modifications of RNA with single-nucleotide resolution and providing quantitative measurements of modification stoichiometry. However, MS analysis of RNA is complicated by myriad sample matrix components that are incompatible with MS, contributing to RNA signal suppression or creating substantial data analysis challenges. The judicious selection of an appropriate sample preparation method is therefore an essential, yet often overlooked, step prior to MS characterization of RNA.
    Keywords:  Epitranscriptome; Mass spectrometry; Nucleic acids; RNA modification; Sample preparation
    DOI:  https://doi.org/10.1016/j.aca.2026.345154
  27. Methods Enzymol. 2026 ;pii: S0076-6879(25)00523-3. [Epub ahead of print]726 253-267
    Strategies to minimize artificial lipid oxidation in mass spectrometry based epilipidomics analysis.
    Sider Penkov, Gabriele Lombardi Bendoula, Maria Fedorova.
      (Per)oxidized lipids represent a well-studied component of the epilipidome, a subset of the native lipidome formed through both enzymatic and non-enzymatic lipid oxidation. Given their diverse biological roles, including cellular signalling, regulation of immune responses, and modulation of cell death pathways, accurate detection of lipid peroxidation products is essential. Mass spectrometry-based approaches have become the method of choice for the sensitive, multiplexed detection and structural characterization of oxidized lipids across a variety of biological samples. However, the structural features of lipids, particularly the presence of acyl chains containing multiple double bonds, render them susceptible not only to endogenous oxidation but also to artificial oxidation during sample preparation prior to analysis. Consequently, special care must be taken throughout sample collection, storage, and lipid extraction to minimize artefacts arising from lipid autoxidation. Here, we describe protocols developed in our laboratory over recent years aimed at preventing artificial lipid oxidation during sample preparation, with examples spanning biological materials derived from cell culture, animal and human tissue biopsies, and biofluids. Finally, we propose internal quality control procedures to assess the effectiveness of these measures in preventing lipid autoxidation.
    Keywords:  Autoxidation; Epilipidomics; Lipid peroxidation; Quality assurance; Sample preparation
    DOI:  https://doi.org/10.1016/bs.mie.2025.11.019
  28. Anal Chem. 2026 Feb 17.
    FastCCS: A Deep Learning Framework for Accurate Collision Cross-Section Prediction from SMILES with Broad Applications in Cheminformatics and Omics.
    Amir Aghajan, Saeed Masoum, Amir Hossein Alinoori.
      One of the best ways to analyze complex samples is ion-mobility-mass spectrometry (IM-MS). A crucial capability of IM-MS is the ability to compare changes in the analyte structures over time. In analytical and structural chemistry, collision cross-section (CCS) values obtained from IM-MS serve as essential, structure-dependent descriptors. We provide FastCCS, a deep learning system that directly and accurately predicts CCS from SMILES strings and ion adduct types. It was trained on the most chemically diverse CCS dataset, which includes 26 adduct ion states and 23,636 curated molecular structures. Compared with state-of-the-art CCS prediction algorithms, FastCCS achieves a median relative error of 1.7% (R2 = 0.99). FastCCS could be used in mass spectrometry coupled with IMS systems to improve compound identification in complex biological and chemical matrices, which is open-access and available for free via the online interface at www.fastccs.com, and its code is available on GitHub for local running and development. Its accuracy, reproducibility, and robustness relative to existing methodologies are demonstrated by strong benchmarking data. Its universal applicability across multiple chemical spaces underlines its relevance for metabolomics, drug discovery, and environmental research.
    DOI:  https://doi.org/10.1021/acs.analchem.5c06101
  29. Biol Pharm Bull. 2026 ;49(2): 301-309
    Development and Clinical Application of a Simultaneous Liquid Chromatography-Tandem Mass Spectrometry Method for Patients with Graft-versus-Host Disease to Quantify the Plasma Concentrations of Ruxolitinib and Posaconazole.
    Masaki Kumondai, Nagomi Hayashi, Yu Sato, Daisuke Kobayashi, Ayaka Otsuki, Yugo Ueki, Yasushi Onishi, Taku Tsukamoto, Kohei Yoshikawa, Yoshihiro Hayakawa, Yuji Sato, Toshihiro Sato, Mayumi Sato, Masafumi Kikuchi, Masamitsu Maekawa, Nariyasu Mano.
      Graft-versus-host disease (GVHD) is a clinically significant problem with high mortality that is gradually increasing. Ruxolitinib (RUX) is the only drug used for steroid-refractory GVHD treatment and is thereby crucial. Therapeutic drug monitoring of RUX may be effective because of the relationship between the plasma RUX concentration and treatment outcomes. Posaconazole (PCZ) has also been the recent focus of combined treatment with RUX owing to its pharmacokinetics. We established a simultaneous LC-tandem MS (LC-MS/MS) method and performed plasma drug concentration measurements and monitoring using clinical laboratory values for both RUX and PCZ. We also compared our technique to a simple LC-MS/MS method for clinical application. Moreover, the utility of the automated pretreatment LC-MS/MS (auto-LC-MS/MS) method was tested for further applications. The simultaneous quantification LC-MS/MS method satisfied analytical validation criteria under clinical conditions. Our method demonstrated linearity over the range of 0.3-500 ng/mL for RUX and 3-5000 ng/mL for PCZ, with intra- and inter-day precision and accuracy within ±15%. A possible correlation between plasma RUX concentration and kidney injury was observed in 1 of the 6 patients. Notably, plasma PCZ concentrations were decreased by changing the administration route. Moreover, the plasma concentration levels obtained using the auto-LC-MS/MS method were highly concordant with those obtained using the LC-MS/MS method. The validated LC-MS/MS method was found to be useful in clinical applications; thus, further research into its applications in clinical practice is desirable.
    Keywords:  graft-versus-host disease; posaconazole; ruxolitinib; therapeutic drug monitoring
    DOI:  https://doi.org/10.1248/bpb.b25-00646
  30. Bioanalysis. 2026 Feb 19. 1-13
    A simple and highly sensitive LC-MS/MS bioanalytical method for phosphorodiamidate morpholino oligonucleotides in plasma.
    Tsubasa Kameyama, Shunji Imai, Rei Mitamura, Makoto Niwa, Tetsuhiro Yamada, Kazutomi Kusano.
       BACKGROUND: LC-MS/MS is widely used for the quantification of phosphorodiamidate morpholino oligomers, but its low sensitivity is a problem. In addition, solid-phase extraction, a pretreatment method generally used for LC-MS/MS analysis, results in low recovery when applied to phosphorodiamidate morpholino oligomers. Therefore, a highly sensitive bioanalytical method for the determination of phosphorodiamidate morpholino oligomers using LC-MS/MS with improved pretreatment is desired.
    RESULTS: Protein precipitation was applied to LC-MS/MS analysis for viltolarsen, as a typical phosphorodiamidate morpholino oligomer, in plasma, and PPT with MeOH achieved high recoveries (>90%). Reversed-phase liquid chromatography (RPLC) with gradient elution improved ion suppression compared to hydrophilic interaction liquid chromatography. A combination of PPT and RPLC achieved higher sensitivity (lower limit of quantification, 1 ng/mL) than those of approved phosphorodiamidate morpholino oligomers (10 to 20 ng/mL in their clinical reviews), and the between-run accuracy and precision ranged from 97.1% to 109% and 2.56% to 10.5%, respectively. This method was also shown to be applicable to another phosphorodiamidate morpholino oligomer, ψM23D (+07-18).
    CONCLUSION: A simple and highly sensitive bioanalytical method for the determination of viltolarsen was established by optimizing RPLC and PPT, and the method was successfully applied to a phosphorodiamidate morpholino oligomers with a different sequence.
    Keywords:  LC-MS/MS; PMO; high sensitivity bioanalysis; matrix effect; protein precipitation
    DOI:  https://doi.org/10.1080/17576180.2026.2632688
  31. Methods Enzymol. 2026 ;pii: S0076-6879(25)00522-1. [Epub ahead of print]726 217-252
    Detection, imaging and quantification of phosphoinositides using ion chromatography suppressed conductivity and mass spectrometry imaging.
    Artur Lazarian, Krista M Wartchow, Nicholas Bartelo, Laura Beth McIntire.
      Phosphoinositide lipids have been implicated in aging, health and disease. Prior studies have identified enzymes critical for lipid metabolism, such as synthetic and degrading enzymes, which have different specificities based on the composition of the inositol ring as well as specific sub-cellular localization and multiple regulatory pathways. In addition to understanding the regulation of enzyme expression, activity and localization, it is critical to investigate levels of the specific lipids of interest. Current methods for detection and quantification of lipids include high performance liquid chromatography/ion chromatography (HPLC/HPIC) suppressed conductivity detection and mass spectrometry. Isobaric polyphosphorylated lipid species can be differentially separated using HPIC methods based on the differential chemical properties of the phosphorylation sites on the inositol ring, which are not able to be detected by mass spectrometry. However, mass spectrometry has the advantage of detecting the acyl chain composition for the individual species which has been shown to affect the signaling properties of the lipids. Emerging methods using mass spectrometry imaging offer in situ localization of the specific lipids within tissue but do not yet achieve single cell or intracellular spatial resolution. We describe methods for detection of polyphosphorylated phosphoinositides using HPIC and both untargeted and targeted imaging mass spectrometry using matrix-free desorption electrospray ionization. We also provide considerations for optimization of the methods as well as quantification of the resulting high dimensional data. Based on the central role phosphoinositides play in neuronal function and neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, Down Syndrome, and Traumatic Brain Injury, sensitive and accurate detection and quantification is paramount for mechanistic studies as well as biomarker and therapeutic development.
    Keywords:  DESI; Desorption electrospray ionization; HPIC; HPLC; Ion chromatography; Mass spectrometry imaging; PI(4,5)P2; PIP2; Phosphoinositides; Spatial lipidomics; Suppressed conductivity
    DOI:  https://doi.org/10.1016/bs.mie.2025.11.018
  32. Anal Chem. 2026 Feb 16.
    OctoChemDB: An Aggregated Database for Small Molecule Identification Using High-Resolution MS Data.
    Ricardo Silvestre, Rémi Martinent, Laure Menin, Natalia Gasilova, Vincent Mutel, Cyril Portmann, Luc Patiny.
      High-resolution mass spectrometry (HRMS) is a cornerstone technology to dereplicate small molecules by comparing their MS spectral data to references in extensive chemical databases. However, most existing chemical databases lack robust support for processing spectral data or enabling direct m/z-based searches, limiting their usefulness for rapid compound identification. To address this, we developed OctoChemDB, a centralized database that aggregates and harmonizes chemical, biological, and spectral data from multiple open-access resources such as PubChem, MassBank, and GNPS. To make this data programmatically accessible, we implemented a REpresentational State Transfer Application Program Interface (REST API) that allows external tools and software to query the database using customizable parameters. This API serves as the core access point for developers and researchers to integrate OctoChemDB data into their own workflows and applications. As a practical demonstration of how the API can be used, we built a web application, available at https://octochemdb.cheminfo.org/, that enables users to perform m/z-based searches, predict molecular formulas, assess isotopic similarity, analyze fragmentation patterns, and retrieve associated literature and patents. This web interface serves as a user-friendly example of how the underlying database and API can be leveraged to accelerate small molecule identification. We illustrate the utility of the platform through case studies, including the identification of 3,4-methylenedioxymethamphetamine (MDMA) and caffeine, demonstrating its effectiveness in proposing structural hypotheses, matching experimental spectra with database entries, and streamlining dereplication workflows. The entire project, including source code, is available at https://github.com/cheminfo/octochemdb.
    DOI:  https://doi.org/10.1021/acs.analchem.5c06761
  33. Anal Chem. 2026 Feb 19.
    MOESIopt: An Integrated Computational Framework for Automated Restoration of Suboptimal Mass Spectrometry and Optical Emission Spectrometry Images.
    Haonan Mi, Shichao Wei, Xiujun Fu, Zhimin Xia, Yuxing Zhang, Zhentao Tang, Xinxin Wang, Xiaowen Tang, Shuai Liang, Xuelu Ding.
      Mass spectrometry imaging (MSI) and optical emission spectrometry imaging (OESI) are powerful label-free techniques for mapping molecular and elemental distributions in biological and chemical samples. However, these methods often suffer from artifacts such as pixel misalignment, streaking, tailing, and high-frequency noise, which compromise image quality and hinder accurate interpretation. Existing solutions predominantly rely on hardware improvements or manual curation, which are costly and not easily scalable. To address these challenges, we introduce MOESIopt, a modular computational framework that automates the restoration of suboptimal MS and OES images without requiring hardware modifications or high-resolution optical references. MOESIopt incorporates a series of tailored algorithms for low- and high-frequency feature separation, pixel alignment, destreaking, tailing correction, and adaptive filtering. The framework supports common data formats (TXT, CSV) and includes a user-friendly graphical interface for seamless integration into existing workflows. We demonstrate its effectiveness on diverse data sets from LA-DBD-OESI/MSI, IR-MALDESI, nano-DESI, and other platforms, showing significant enhancements in image clarity and structural coherence. As an open-source tool, MOESIopt offers a versatile, open-source solution to advance the reproducibility and accessibility of high-quality chemical imaging.
    DOI:  https://doi.org/10.1021/acs.analchem.5c06898
  34. J Sep Sci. 2026 Feb;49(2): e70376
    Transposition of the Complementary Developing Solvent Technique to Flash Chromatography: A Structured Step-Based Fractionation Strategy for Complex Plant Extracts.
    Jason Fauquet, Adam Ellatiff, Claudio Palmieri, Pierre Duez, Bertrand Blankert, Mathilde Wells, Amandine Nachtergael.
      The Complementary Developing Solvent technique, originally developed for high-performance thin-layer chromatography, employs solvent systems with distinct polarity ranges to achieve enhanced chromatographic resolution while covering a broad chemical space. This study demonstrates the successful adaptation of low polarity developing solvent and high polarity developing solvent systems to normal-phase flash chromatography for systematic fractionation. The system suitability test used in high-performance thin layer chromatography, namely the Universal HPTLC Mix, enabled direct comparisons between high-performance thin layer chromatography and flash chromatography, demonstrating a conserved polarity-driven retention hierarchy across chromatographic scales. To confirm compound identities and elution order, each chromatographic peak was collected and analyzed by tandem mass spectrometry, with MS/MS spectra manually matched against reference standards. Quantitative chromatographic performance was benchmarked using effective peak capacity (Pc), yielding a value of 16.41 for the high-polarity developing system, indicative of a globally balanced separation. In addition, a systematic isocratic step fractionation strategy was implemented by segmenting each elution gradient (low polarity developing solvent and high polarity developing solvent) into seven predefined polarity windows. This strategy was applied on a crude methanolic extract of Sideritis scardica Griseb., confirming robust and reproducible fractionation boundaries in a complex botanical matrix. Collecting a single fraction per isocratic step significantly reduces the number of samples for subsequent analysis such as bioassays and untargeted metabolomic profiling, thereby accelerating natural product discovery and dereplication workflows.
    Keywords:  HPTLC‐to‐flash transposition; Universal HPTLC Mix; isocratic step fractionation; preparative chromatography workflow; untargeted metabolomics workflow
    DOI:  https://doi.org/10.1002/jssc.70376
  35. Anal Bioanal Chem. 2026 Feb 19.
    Mixed sorbent in miniaturized stir bar sorptive dispersive microextraction for the determination of gut microbiome metabolites in plasma samples.
    Cristian Azorín, Sara R Fernandes, Luisa Barreiros, Juan L Benedé, Alberto Chisvert, Marcela A Segundo.
      An analytical method for the simultaneous determination of three gut microbiome metabolites related to the gut-brain axis (trimethylamine N-oxide (TMAO), phenylacetylglutamine (PAG), and 4-ethylphenyl sulfate (EPS)) in human plasma is presented. The proposed method is based on miniaturized stir bar sorptive dispersive microextraction (mSBSDME) followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In this work, a magnetic composite made of CoFe2O4 magnetic nanoparticles embedded into a mixture of commercial sorbents (hydrophilic-lipophilic balance and mixed-mode cation exchange) was employed as magnetic sorbent material, taking advantage of its affinity to the target analytes. Under the optimized conditions, the method was validated and showed good analytical features in terms of linearity (at least up to 1000 ng mL-1), limits of detection (22, 2, and 9 ng mL-1 for TMAO, PAG, and EPS, respectively), repeatability (RSD ≤ 10%), and accuracy (91-101%). Moreover, relative recoveries between 84 and 104% were obtained, showing matrix effects were negligible using deuterated standards as surrogates. This new approach was successfully applied to clinical samples, allowing the rapid determination of the target metabolites in a single run for the first time.
    Keywords:  Gut microbiome metabolites; Hydrophilic interaction liquid chromatography; Low-volume samples; Miniaturized stir bar sorptive dispersive microextraction; Plasma
    DOI:  https://doi.org/10.1007/s00216-026-06391-8
  36. ACS Omega. 2026 Feb 10. 11(5): 7388-7395
    Exploring Approaches for Accelerated Mass Spectrometric Detection of Fluorochemicals from Aqueous Solutions Using Indirect, Adsorbent-Facilitated Desorption Ionization.
    Nathan R Bays, Samantha M Kruse, Mohammad Shohel, Jessica A LaFond, David Schafer, Brynal A Benally, Trinity M Griffus, Jessica Román-Kustas, Jessica N Kruichak, Mark J Rigali, Andrew W Knight, Ryan D Davis.
      There is a growing need for rapid, low-cost analytical tools to screen water supplies for persistent contaminants. Due to their ubiquitous presence in the environment and their detrimental effects on human health, there is a public interest in widespread testing for perfluoroalkyl substances (PFAS). However, the most common methods for PFAS analysis can be time-intensive, requiring a preconcentration step followed by liquid chromatography-mass spectrometry (LC-MS), and are cost-prohibitive for most members of the public. To address these challenges, this study explores a novel method for rapid analysis of aqueous analytes by concentrating analytes on solid adsorbents and detecting them using mass spectrometric analysis via desorption ionization directly from the adsorbent surface. We demonstrate this general approach of indirect solution analysis (ISA) with desorption electrospray ionization (ISA-DESI) and laser desorption ionization (ISA-LDI). Various adsorbent materials were screened, including commercial mesoporous carbons, alumina, and metal-organic frameworks (MOFs). Using ISA-DESI, we consistently detect concentrations as low as 5-100 parts per trillion (ppt) for perfluorooctanoic acid (PFOA) and 10-100 ppt for perfluoroundecanoic acid (PFUnDA). This approach enables rapid detection in under 5 min, making it suitable for applications requiring trace detection with fast response times. We further demonstrate the use of ISA-DESI on a range of environmentally relevant contaminants. Advantages of this indirect solution analysis approach include simplified sample preparation, accelerated analysis, and low cost with readily available materials, making it a promising tool to accelerate mass spectrometric PFAS detection for identifying contaminated sites, performing laboratory studies, and monitoring industrial waste streams.
    DOI:  https://doi.org/10.1021/acsomega.5c08128
  37. Front Plant Sci. 2025 ;16 1687705
    Comparative analysis of metabolites in different Areca inflorescence tissues based on spatial metabolomics.
    Xinyu Wen, Panjing Li, Linbi Zhang, Han Li, Fusun Yang.
      In this study, we focused on the spatial distribution of metabolites in areca palm (Areca catechu L.) floral organs. Using spatial metabolomics, the composition and accumulation patterns of active metabolites were delineated to provide a basis for the development and utilization of their bioactive compounds. The present study combined untargeted metabolomics and mass spectrometry imaging, enabling high-resolution spatial visualization of metabolites in floral tissue microregions, with an emphasis on alkaloids, flavonoids, coumarins, and cinnamic acid. Significant differences in metabolite contents were observed using statistical methods and spatial metabolic mass spectrometry, revealing how these metabolites clustered and varied across tissues. Areca alkaloids exhibited specific enrichment in the ovary locules and ovule tissues of female flowers, showing concentrations 3-5 times higher than those in other tissues. Flavonoids were primarily localized in the vascular bundle sheath cells of the ovary wall. Although coumarins and cassia bark acids were distributed across all four tissue types, they displayed a gradient distribution pattern in the epidermal layer of female flower ovules. Using spatial metabolomics, this research reveals the compartmentalized distribution of metabolites across A. catechu floral organs, shedding light on their tissue-specific functions and related metabolic pathways.
    Keywords:  Areca catechu; alkaloids; floral organs; sex differentiation; spatial metabolomics
    DOI:  https://doi.org/10.3389/fpls.2025.1687705
  38. Talanta. 2026 Feb 07. pii: S0039-9140(26)00176-1. [Epub ahead of print]304 129521
    Rapid magnetic solid-phase extraction approach employing a modified graphene oxide nanomaterial for the determination of 20 pharmaceuticals and transformation products in treated urban wastewater.
    Ana Belén Martínez-Piernas, Irene Sánchez-Trujillo, Carlos Vereda-Alonso, María Del Mar López-Guerrero, Elisa Isabel Vereda-Alonso.
      A magnetic solid-phase extraction (MSPE) method based on a green magnetic graphene oxide material (d-M@GO) was developed and validated for the simultaneous determination of 20 contaminants of emerging concern (CECs), including pharmaceuticals and transformation products, in wastewater using liquid chromatography-high-resolution mass spectrometry (LC-HRMS). The adsorption behaviour of analytes on d-M@GO was investigated through kinetic and equilibrium modelling, indicating mass-transfer-limited adsorption consistent with a linear isotherm. A two-zone kinetic model, accounting for fast and slow adsorption regions, provided the best fitting for most compounds, confirming the coexistence of easily accessible and diffusion-limited adsorption sites. The MSPE procedure was optimised to establish the most efficient adsorption and elution conditions. Method validation in treated urban wastewater demonstrated its suitability as a green alternative to conventional solid-phase extraction. Eighteen of the twenty analytes showed recoveries between 70% and 120%, with RSDs below 20%. Low method quantification limits (MQLs) were determined, ranging from 2 to 20 ng/L. Application of the method for the analysis of five wastewater samples enabled the quantification of up to 19 analytes at concentrations ranging from 6.37 to 1321 ng/L. In addition, non-target screening using MS-DIAL open-source software (a platform for untargeted metabolomics and lipidomics data processing) expanded the analytical scope, allowing the tentative identification of 24 additional CECs, five of which were confirmed using reference standards. The combination of target and non-target analyses demonstrates the capability of the method for comprehensive monitoring of CECs in wastewater. With a 60-70% lower carbon footprint than conventional SPE approaches, the d-M@GO-MSPE-LC-HRMS workflow represents a robust, rapid, and sustainable solution.
    Keywords:  CECs; Emerging contaminants; LC-HRMS; MSPE; Magnetic graphene oxide; Wastewater
    DOI:  https://doi.org/10.1016/j.talanta.2026.129521
  39. Curr Opin Clin Nutr Metab Care. 2026 Feb 19.
    Measuring nutrient content in human milk: are we there yet?
    Donna T Geddes, Lisa Stinson.
       PURPOSE OF REVIEW: Precise nutrient quantification is essential for developing reference values, guiding fortification strategies and preventing growth deficits, particularly in preterm infants. This review examines current methodologies for measuring nutrient content in human milk, evaluating accuracy, practicality, and limitations of existing analytical approaches.
    RECENT FINDINGS: Current analytical methods for human milk nutrients demonstrate a trade-off between accuracy and clinical practicality. While some methods provide the high accuracy for macronutrient measurement, they require large sample volumes and extensive laboratory time. Alternative approaches such as spectroscopic and colorimetric methods offer improved efficiency and smaller sample requirements but with varying degrees of accuracy. Significant methodological challenges persist across all approaches, including the lack of standardized sampling protocols that account for temporal variation in milk composition, and difficulties in adapting analytical technologies originally designed for other matrices. These limitations are particularly problematic for micronutrient analysis, where sample degradation and storage conditions could impact results.
    SUMMARY: While multiple analytical approaches for human milk exist, significant methodological limitations compromise accuracy and clinical utility. The field requires standardized workflows encompassing rigorous sampling protocols, validated storage conditions, and comprehensive method validation. Future developments should bridge the gap between research-grade accuracy and clinical practicality.
    Keywords:  breast milk; breastfeeding; composition; human milk; macronutrients; micronutrients; nutrients
    DOI:  https://doi.org/10.1097/MCO.0000000000001214
  40. Anal Chim Acta. 2026 Apr 01. pii: S0003-2670(26)00136-4. [Epub ahead of print]1393 345186
    A multi-functional effervescent tablet for one-pot effervescent/derivatization/extraction: An integrated strategy for sulfonamide residue analysis.
    Di Chen, Yixin Ma, Xirui Pei, Wenxuan Li, Chenqi Niu, Haobo Zheng.
       BACKGROUND: Sulfonamides are extensively used antimicrobials, but residues in food raise health risks such as allergies, antimicrobial resistance, and carcinogenicity. Strict residue limits require sensitive and efficient monitoring methods. While LC-FLD is selective and practical, conventional workflows rely on multi-step extraction and derivatization, which are time-consuming. A streamlined strategy integrating extraction and derivatization into a single operation is needed for practical residue analysis in complex food matrices.
    RESULTS: A novel multi-functional effervescent tablet was developed to unify effervescence, derivatization, and extraction in one step. The tablet incorporates effervescent precursors (Na2CO3/NaH2PO4), fluorescamine (a derivatization reagent), Fe3O4 nanoparticles, and hydroxylated multi-walled carbon nanotubes (an adsorbent). Upon immersion, CO2 bubbles promote rapid dispersion of reagents and in-situ assembly of a magnetic composite adsorbent, enabling simultaneous derivatization and efficient extraction of sulfonamides. The core tablet-mediated procedure requires only 4 min, with desorption achieved in 0.5 min using acetone. Validation demonstrated excellent linearity (R2 > 0.998), low detection limits (0.130-0.285 ng/g), and recoveries of 82.6-107.0% with RSDs <10%. Application to spiked honey confirmed accuracy, with relative errors ranging from -8.9% to +9.2%. Comparative studies showed performance equivalent to conventional multi-step protocols, while reducing handling steps and solvent use during the extraction phase.
    SIGNIFICANCE: This integrated effervescence/derivatization/extraction strategy streamlines sulfonamide residue analysis into a rapid, cost-effective, and easily automatable workflow. While sample pretreatment is still required for complex matrices, the tablet-based step significantly reduces manual handling and solvent consumption during the extraction and derivatization process. Its compatibility with LC-FLD provides a practical and cost-effective alternative to LC-MS, supporting reliable food safety surveillance within regulatory standards.
    Keywords:  Effervescence-assisted extraction; Food safety; Liquid chromatography-fluorescence detection; One-pot method; Sulfonamide residue analysis
    DOI:  https://doi.org/10.1016/j.aca.2026.345186
  41. Anal Bioanal Chem. 2026 Feb 16.
    Rapid differentiation of D/L-homocysteine, D/L-homocystine, and S-allyl-D/L-cysteine using ion mobility-mass spectrometry.
    Xiang Li, Ling Ling, Chaoxian Chi, Chuan-Fan Ding.
      The development of a rapid analytical method for distinguishing chiral sulfur-containing compounds is essential due to the significant differences in biological activity exhibited by different enantiomers. This work presents a straightforward and rapid method for the chiral discrimination of D/L-homocysteine (D/L-Hcy), D/L-homocystine (D/L-Hcy2), and S-allyl-D/L-cysteine (D/L-SAC) using cyclodextrin (CD) and metal adducts in conjunction with ion mobility-mass spectrometry (IM-MS). Through the formation of ternary complexes, separation was achieved with IM peak resolutions of 1.41 for [α-CD+D/L-Hcy+Co-H]+, 1.24 for [α-CD+D/L-Hcy2+Ca-H]+, and 1.65 for [β-CD+D/L-SAC+Fe-H]+. Theoretical calculations were performed to identify the optimal conformations of these ternary complexes. Conformational analysis elucidated distinct structural differences at the molecular level, providing insight into the chiral separation mechanism. Owing to its superior resolving power, this method enables the direct quantification of D/L enantiomers in mixtures. It was successfully applied to the determination of D/L-SAC in garlic samples, obviating the need for laborious sample pretreatment or derivatization steps. Overall, this work establishes a robust analytical platform for the chiral analysis of sulfur-containing amino acids and their derivatives.
    Keywords:  Chiral sulfur-containing compounds; Homocysteine; Homocystine; Ion mobility-mass spectrometry; S-Allyl-cysteine; Ternary complex
    DOI:  https://doi.org/10.1007/s00216-026-06378-5
  42. Methods Enzymol. 2026 ;pii: S0076-6879(25)00491-4. [Epub ahead of print]726 289-319
    Metabolic labeling of glycerophospholipids.
    Robert J Maraski, Christelle F Ancajas, Jinchao Lou, Michael D Best.
      The approach of metabolic labeling provides an invaluable tool for elucidating previously unknown and poorly understood metabolic processes within cells. By introducing clickable versions of substrates into cells, the products of these biomolecule mimics can be conveniently tracked via post-derivatization of the clickable tag with a variety of reporter groups. Here, we will describe lipid metabolic labeling as an invaluable approach for interrogating lipid metabolic pathways, which can yield crucial information regarding complex lipid biosynthesis and trafficking networks that can open new therapeutic targets involving downstream natural products. In this chapter, we present detailed experimental procedures for the development of clickable serine probes for the labeling of phosphatidylserine (PS) and other lipids, including probe design and synthesis as well as analysis of biological incorporation via confocal microscopy, thin-layer chromatography (TLC), and liquid chromatography mass spectrometry (LCMS). This strategy provides a powerful approach for interrogating lipid biosynthetic pathways centered around PS.
    Keywords:  Click chemistry; Fluorescence microscopy; Lipids; Membranes; Metabolic labeling; Phosphatidylserine; Phospholipids
    DOI:  https://doi.org/10.1016/bs.mie.2025.11.010
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