bims-metlip 2026-03-29 papers

bims-metlip

Biomed News

on Methods and protocols in metabolomics and lipidomics

Issue of 2026–03–29
thirty papers selected by
Sofia Costa, Matterworks

Per- and Polyfluoroalkyl Substances (PFAS) in Michigan: A Novel High-Throughput Method with Liquid Chromatography-Mass Spectrometry (LC-MS/MS) Analysis of 42 PFAS Compounds in Human and Bovine Serum.
Determination of the pyrrolo[2,3-d] pyrimidine antifolate AGF94 from a preclinical murine study using a simple UHPLC-MS/MS assay.
Accurate and Sensitive UHPLC-Tandem Mass Spectrometry Sequential Methods for Therapeutic Drug Monitoring of Aztreonam/Avibactam in Human Plasma.
SMASH Imaging: A Serial Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Strategy for High-Resolution Imaging Facilitates Dual-Polarity and MS2 Spatial Lipidomics on a Single Tissue Section.
Direct Infusion Acoustic Droplet Ejection Mass Spectrometry: Enabling High-Throughput Shotgun Lipidomics.
Enantioselective Chiral Separation and Quantitation of PI3Kγ Inhibitor Eganelisib in Rat Plasma Using UHPLC-MS/MS: Application to Evaluate Pharmacokinetic Study.
Beyond compound‑specific methods: Group‑specific UHPLC-MS/MS enables rapid detection and quantitation of all glucosinolates.
Decoding the Metabolic Signatures of Neurodegeneration Diseases: Advances in Mass Spectrometry-Based Metabolomics.
Overcoming missing data in spatial metabolomics with machine learning imputation to accelerate downstream discovery.
Protocol to purify fatty acid metabolites with two approaches for quantification using liquid chromatography-mass spectrometry.
A Minimally Invasive LC-MS/MS Approach for Assessing Endocannabinoids in Saliva and Capillary Blood Microsamples.
Chromatography and mass spectrometry in therapeutic drug monitoring: Method performance, practical trade-offs, and implementation considerations.
Simultaneous Determination of Venetoclax and Posaconazole in Human Plasma by UPLC-MS/MS: Application to Therapeutic Drug Monitoring in Acute Myeloid Leukemia Patients.
Enhanced Untargeted Metabolomics Based on High-Resolution Mass Spectrometry Reveals Global Rewiring Due to Mitochondrial Dysfunction in Yeast.
AI redefine untargeted metabolomics: estimating chemical amounts for a Human Exposome Project.
Development and Validation of SEC-UV/HRMS Procedure for Simultaneous Determination of BSA and Its Association Products.
S-Adenosylmethionine (SAM) and S-Adenosylhomocysteine (SAH) Monitoring Using Analytical Methods in Clinical Laboratory Practice: Where Are We?
Future perspectives in mass spectrometry of plant lipids.
Dielectric barrier discharge ionization (DBDI) enables rapid analysis of new psychoactive substances with ion mobility-mass spectrometry.
Unified Multitask Modeling for Retention Time Prediction Across Chromatographic Conditions.
Pharmacokinetics, Bioavailability, and Metabolism of Zongertinib, a Novel HER2-Selective Tyrosine Kinase Inhibitor, in Rat by Liquid Chromatography Hyphenated With Electrospray Ionization Tandem Mass Spectrometry.
Fully Automated Serum LC-MS/MS Platform and Pediatric Reference Intervals for Organic Acids, Amino Acids, and Acylcarnitines in Children (Ages 0-6 Years): Toward Quantitative Diagnosis of Inborn Errors of Metabolism.
Simultaneous Determination of Multiclass Cyanotoxins in Aquatic Products, Vegetables and Algal Dietary Supplements Using Dispersive Solid-Phase Extraction (dSPE)-UHPLC-MS/MS.
Matrix Effect Variability in Urine Samples from Different Cohorts and Implications on LC-ESI-MS Mycotoxin Biomarker Analysis.
Comprehensive profiling of arsenosugars in algae using UHPLC-HRMS and UHPLC-IMS-Q-TOF.
Environmental occurrence of amantadine and rimantadine in aquaculture pond sediments: application of a newly developed LC-MS/MS method.
Quantification of Macular Carotenoids over a Wide Dynamic Range in Plant Matrices and Caco-2 Cells Using a Single Transferable Analytical Method.
Single Laboratory Validation of a Liquid Chromatography-Tandem Mass Spectrometry Method for the Quantitation of Microcystins in Marine and Estuarine Shellfish.
Characterization of siRNA product-related impurities by hydrophilic interaction liquid chromatography (HILIC) coupled with mass spectrometry.
Signals of Diagnostic Product Ions of Kavalactones in Their ESI Mass Spectra-Implications for Isomer Differentiation and Identification of Kavalactone Conjugates.

Toxics. 2026 Feb 28. pii: 209. [Epub ahead of print]14(3):

Per- and Polyfluoroalkyl Substances (PFAS) in Michigan: A Novel High-Throughput Method with Liquid Chromatography-Mass Spectrometry (LC-MS/MS) Analysis of 42 PFAS Compounds in Human and Bovine Serum.

Jessica M Morrison, Douglas J Carmack, Sarah Y Lockwood-O'Brien, Chelsea A Bielicki, Julia R Feeley, Robert L Frisk, Timothy A Karrer.

  A novel method for the analysis of per- and polyfluoroalkyl substances (PFAS) in serum is presented here, utilizing a matrix-matched calibration curve, small sample size, high-throughput sample prep with a protein crash and filtration, resulting in a concentrated and purified sample, which is analyzed via liquid chromatography (LC) mass spectrometry (MS, LC-MS/MS). As part of the validation of this method, accuracy, precision, reportable range verification, sensitivity, carryover, recovery, specificity, interferences, maximum dilutions, and stability are presented. This method quantitates 42 PFAS compounds across a wide variety of compound classes and has limits of detection in the low ng L-1 range with all analytes having a limit of quantitation less than the first calibrator (25 ng L-1). Total method accuracy was >91%, exceeding the set performance criteria goal of ≥85%. Method imprecision was <11%, exceeding the set performance criteria goal of ≤15%. Method recovery averaged 85%. Limited and minimal matrix effects were seen. Interference from bile acids was found to be of no concern at biologically relevant concentrations for this method. This method has been successfully employed in biomonitoring studies for residents of Michigan over the past eight years.

Keywords:  analytical sample preparation methods; biological monitoring; environmental monitoring; fluorocarbons; liquid chromatography–mass spectrometry; serum

DOI:  https://doi.org/10.3390/toxics14030209
J Chromatogr B Analyt Technol Biomed Life Sci. 2025 Dec 15. pii: S1570-0232(25)00387-3. [Epub ahead of print]1267 124833

Determination of the pyrrolo[2,3-d] pyrimidine antifolate AGF94 from a preclinical murine study using a simple UHPLC-MS/MS assay.

Tryston T Metz, Rachel C Ashe, Alexis C Duncan, Ethan C Wilner, Keith T Schmidt, Kristbjorn O Gudmundsson, Zhanjun Hou, Aleem Gangjee, Larry H Matherly, Serguei V Kozlov, William D Figg.

  A UHPLC-MS/MS method for the detection and quantification of the 6-substituted pyrrolo[2,3-d] pyrimidine AGF94, a novel antifolate, in mouse plasma and tissue was developed and validated. The developed method relies on a simple protein precipitation with methanol, followed by separation on a C18 column using a gradient solvent system of acetonitrile and water with 0.1 % formic acid in both. Detection and quantification of AGF94 were achieved by multiple reaction monitoring using a Sciex QTRAP 5500 mass spectrometer operated in positive electrospray ionization mode. The transitions for AGF94 and the internal standard were m/z 448 to 137 and 442 to 295, respectively. The calibration curve ranged from 5 to 500 ng/mL in mouse plasma with a linearity of R2 = 0.99611 ± 0.00280 across multiple days. Accuracy of the assay ranged from -6.22 to 5.56 % and precision was less than 11.58 % off from nominal concentrations. Benchtop, freeze/thaw cycling, and autosampler stabilities did not indicate any substantial changes in concentrations during processing. The overall process efficiency was greater than 96 % for both the analyte and internal standard. The precision and accuracy of the assay were established, and the assay was utilized to analyze preclinical samples from a pharmacokinetic study using AGF94 in a murine pancreatic cancer model. Pharmacokinetic parameters from a noncompartmental analysis of AGF94 in multiple matrices were reported utilizing the validated method.

Keywords:  Antifolates; Bioanalytical method; Mass spectrometry; Preclinical study; UHPLC

DOI:  https://doi.org/10.1016/j.jchromb.2025.124833
Pharmaceutics. 2026 Mar 19. pii: 377. [Epub ahead of print]18(3):

Accurate and Sensitive UHPLC-Tandem Mass Spectrometry Sequential Methods for Therapeutic Drug Monitoring of Aztreonam/Avibactam in Human Plasma.

Ilaria Trozzi, Beatrice Giorgi, Riccardo De Paola, Milo Gatti, Federico Pea.

  Background/Objectives: The aztreonam/avibactam combination represents a promising therapeutic option for severe infections caused by multidrug-resistant Gram-negative pathogens, particularly in critically ill patients. Due to marked pharmacokinetic variability and the need to achieve joint pharmacokinetic/pharmacodynamic (PK/PD) targets of both agents, therapeutic drug monitoring (TDM) may play a pivotal role in optimizing treatment. This study aimed to develop and validate two rapid, accurate, and sensitive UHPLC-qTOF MS/MS sequential methods for quantifying aztreonam and avibactam in human plasma, suitable for routine clinical TDM. Methods: Plasma concentrations were determined by means of ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-qTOF MS/MS), operating in positive and negative electrospray ionization modes for aztreonam and avibactam, respectively. Sample preparation consisted of protein precipitation with isotopically labeled internal standards. The method's validation was performed according to the European Medicines Agency guidelines, by assessing selectivity, linearity, precision, accuracy, recovery, matrix effects, carry-over, and stability. Clinical applicability was evaluated by reprocessing plasma samples, which were already previously collected for routine clinical practice from 20 hospitalized patients undergoing treatment with ceftazidime-avibactam plus aztreonam. Results: The methods showed excellent linearity (R2 ≥ 0.999) over ranges of 0.2-100 µg/mL for aztreonam and 0.1-50 µg/mL for avibactam. Lower limits of quantification were 0.2 µg/mL and 0.1 µg/mL, respectively. Intra- and inter-day precision and accuracy met the EMA criteria at all of the quality control levels. Extraction recovery exceeded 90% for both analytes, and matrix effects were effectively compensated by internal standards. Stability testing highlighted the need for careful sample handling, particularly for aztreonam under repeated freeze-thaw conditions. Clinical application revealed substantial inter-individual variability in steady-state concentrations. Conclusions: The validated UHPLC-qTOF MS/MS assays provide robust and sensitive sequential quantification of aztreonam and avibactam in human plasma, supporting TDM-guided dose optimization in clinical practice.

Keywords:  UHPLC–qTOF MS/MS; aztreonam/avibactam; bioanalytical method validation; high-resolution mass spectrometry; human plasma; therapeutic drug monitoring; β-lactam/β-lactamase inhibitor antibiotics

DOI:  https://doi.org/10.3390/pharmaceutics18030377
Anal Chem. 2026 Mar 26.

SMASH Imaging: A Serial Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Strategy for High-Resolution Imaging Facilitates Dual-Polarity and MS2 Spatial Lipidomics on a Single Tissue Section.

Haruki Uchino, Hiroshi Tsugawa, Makoto Arita.

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is a key technology in spatial lipidomics that provides high sensitivity and spatial resolution. Because of the ionization preference of lipid classes and the lack of detailed structural information without MS2 data, dual-polarity analyses and the acquisition of MS/MS spectra are essential to improve coverage and annotation accuracy. Multitime MSI analyses of the same tissue section can provide seamless integration of multimodal spatial data. However, the feasibility of performing serial MALDI-MSI for the same pixels with high spatial resolution has not been fully evaluated. Here, we present SMASH imaging for dual-polarity and MS2 spatial lipidomics in a single tissue section. We estimated two characteristic matrix compounds, 2,5-dihydroxyacetophenone and trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malononitrile, for dual-polarity analyses and defined the feasible number of layers of SMASH imaging via the coefficient of determination (R2). SMASH imaging successfully visualized over 400 lipid species on average with a 30 μm resolution, with annotation criteria S/N ≥ 50, m/z ≤ 10 mDa, and collision cross section ≤ 20 Å2. In four layers of SMASH imaging, the molecular species of 18 lipids were characterized based on MS2 spectra evidence using parallel accumulation-serial fragmentation on a single mouse brain section. Moreover, eight layers of SMASH imaging with a 5 μm spatial resolution annotated 25 lipid species, supported by a spatial correlation metric between multimodal data. Our approach provides multimodal spatial lipidomics to create a lipidome atlas with accurate annotation and high spatial resolution on a single tissue section.

DOI: https://doi.org/10.1021/acs.analchem.5c03738
Anal Chem. 2026 Mar 25.

Direct Infusion Acoustic Droplet Ejection Mass Spectrometry: Enabling High-Throughput Shotgun Lipidomics.

Yu Zhang, Amy Harms, Lucas Jurado-Fasoli, Jonatan R Ruiz, Nicolas Drouin, Thomas Hankemeier.

High-throughput lipidomics is increasingly important for large-scale studies and clinical applications. While shotgun lipidomics enables rapid analysis, it suffers from limitations such as carryover, ion suppression, and limited structural specificity. Acoustic droplet ejection mass spectrometry (ADE-MS) presents a novel approach, enabling touchless nanoliter-scale sample introduction at high speed, precision, and accuracy. Initially designed for single-droplet injection, ADE-MS was adapted for direct infusion with stable signals. In this study, we developed and benchmarked a scalable workflow based on ADE-MS/MS with parallel reaction monitoring (PRM) on a ZenoTOF MS platform implemented in a 384-well format. By optimizing solvent composition, droplet parameters, and MS acquisition settings, the workflow enabled reproducible quantification of over 1000 polar and nonpolar lipid species across 14 subclasses, with low sample consumption and a total run time of approximately five minutes per sample. Applying this method to NIST SRM 1950 plasma, a total of 731 lipid species were quantified. The method demonstrated robust analytical performance in terms of linearity, precision, reproducibility, and recovery across 384-well microplates. Cross-platform comparison with a validated hydrophilic interaction liquid chromatography (HILIC)-MS/MS method using NIST SRM 1950 plasma demonstrated strong agreement (R2 > 0.80 for most subclasses) and substantially higher throughput, achieving over 200 lipid identifications per minute and a daily capacity exceeding 280 samples. The applicability of this workflow was demonstrated by identifying 656 differential lipid features associated with progressive lipidomic dysregulation across body mass index categories.

DOI: https://doi.org/10.1021/acs.analchem.5c05763
Chirality. 2026 Apr;38(4): e70095

Enantioselective Chiral Separation and Quantitation of PI3Kγ Inhibitor Eganelisib in Rat Plasma Using UHPLC-MS/MS: Application to Evaluate Pharmacokinetic Study.

A R Priyadharshni, Jony Susanna Kandula, Dayasagar Rajiv Karkile, Kale Shyam Shirishkumar, Keyur Parmar, P Radhakrishnanand.

  Eganelisib (EGN, IPI-549), an investigational new drug, is a potent first-in-class PI3Kγ inhibitor with high selectivity compared to other class I PI3K isoforms, with one asymmetric center. Enantiomers have similar physicochemical properties but differ in their biological characteristics, like absorption, distribution, metabolism, and excretion. Hence, a suitable analytical approach is required to investigate the enantioselective behavior in ADME-Tox. In the current study, a sensitive, reliable, and precise chiral LC-MS/MS method has been developed for quantifying EGN enantiomers in rat plasma, in accordance with USFDA guidelines. Enantiomeric separation was achieved within 15 min on a Chiralpak-IK-3 (250 × 4.6 mm, 3 μm) immobilized polysaccharide column, containing 10 mM ammonium bicarbonate and a premixed mixture of acetonitrile and methanol (80:20 v/v) as the mobile phase in the ratio of 10:90 (v/v), with isocratic elution at a flow rate of 0.6 mL/min. Multiple reaction monitoring (MRM) mode was used to detect EGN and SOF in positive electrospray ionization (ESI) mode, characterized by their transitions at m/z 529.3→326.3, 161.1, and m/z 465.1→447.1, 270.2, 252.1. The method demonstrated a linear response in the range of 1-600 ng/mL for both enantiomers, with a lower limit of quantification of 1 ng/mL. The validated bioanalytical method was applied to evaluate the enantioselective pharmacokinetics of EGN enantiomers in rat plasma for the first time, utilizing a model-independent approach. The (R)-enantiomer showed relative fold differences in Cmax, t1/2, AUC0-t, and AUC0-∞ when compared to the (S)-enantiomer, indicating the enantioselective behavior of EGN enantiomers.

Keywords:  Eganelisib; UHPLC–MS/MS; chiral; enantiomer; enantioselective pharmacokinetics

DOI:  https://doi.org/10.1002/chir.70095
J Chromatogr A. 2026 Mar 20. pii: S0021-9673(26)00243-8. [Epub ahead of print]1775 466913

Beyond compound‑specific methods: Group‑specific UHPLC-MS/MS enables rapid detection and quantitation of all glucosinolates.

Ville Fock, Niko Luntamo, Juha-Pekka Salminen.

  Glucosinolates are widely consumed specialized metabolites predominantly found in the Brassicaceae family. Existing analytical methods typically target only specific subsets of glucosinolates and therefore lack the versatility required for comprehensive glucosinolate screening. Hence, there is a gap in analytical methods targeting glucosinolates that can detect any glucosinolate within a given matrix. In this study, targeted compound group‑specific multiple reaction monitoring (MRM) and parallel reaction monitoring (PRM) methods were developed and validated for comprehensive qualitative and quantitative profiling of glucosinolates. Among all glucosinolate group-specific fragment ions evaluated, five (m/z 96, 97, 241, 259, and 275) were selected for product ion optimization and method validation. Of the fifteen transitions selected for method validation, four were retained in the final MRM method based on sensitivity and selectivity. Additionally, the performances of the group-specific methods were compared against simultaneously created compound-specific MRM methods. Although the more traditional compound‑specific methods offered slightly improved sensitivity, they were limited to detect only individual glucosinolates. While detecting whole glucosinolate groups, the group‑specific MRM methods showed lowest limits of detection (LOD) ranging from 11.5 to 87.3 ng/mL, and the upper limits of quantitation (ULOQ) from 2.5 to 55 µg/mL. High‑resolution group-specific PRM methods enabled accurate glucosinolate characterization and yielded LODs for the best precursor ion m/z 259 between 44.1 and 473.6 ng/mL, with ULOQs ranging from 8 to 50 µg/mL. Application of the methods demonstrated their capability to detect 51 distinct glucosinolates across 19 plant species.

Keywords:  Glucosinolate; Group-specific; LC-MS/MS; MRM; Mass spectrometry; PRM

DOI:  https://doi.org/10.1016/j.chroma.2026.466913
Metabolites. 2026 Mar 20. pii: 206. [Epub ahead of print]16(3):

Decoding the Metabolic Signatures of Neurodegeneration Diseases: Advances in Mass Spectrometry-Based Metabolomics.

Md Abdul Hakim, Li Li.

  The dysregulation of multiple metabolic pathways is a potential contributor to the development of neurodegenerative diseases. Understanding early-stage metabolic alterations is crucial for identifying targets associated with disease development and progression. Recent advances in mass spectrometry-based metabolomics now allow investigators to conduct a comprehensive analysis of small-molecule metabolites in complex biological systems, providing valuable insights regarding the biochemical mechanisms underlying neurodegeneration. This review presents the latest advances in mass spectrometry-based metabolomic approaches and their applications in studying neurodegenerative diseases. We discuss methodology improvements in metabolomics, including sample preparation, chromatography separations, ionization, and fragmentation. These improvements enable broader detection and more accurate identification of metabolites. We also review developments in bioinformatics tools for large-scale data processing, structural annotation, and pathway analysis. Furthermore, the signature metabolites associated with major neurodegenerative diseases and the key metabolic pathways involved are summarized. Finally, we address current analytical and biological challenges in mass spectrometry-based metabolomics while exploring its future directions in translational research.

Keywords:  biomarker discovery; mass spectrometry; metabolomic pathways; metabolomics; neurodegenerative diseases

DOI:  https://doi.org/10.3390/metabo16030206
iScience. 2026 Apr 17. 29(4): 115203

Overcoming missing data in spatial metabolomics with machine learning imputation to accelerate downstream discovery.

Tingze Feng, Yuhan Wang, Shaojun Pei, Qiuping Wang, Yirong Li, Jing Lv, Tian Xia, Di Chen, Hai-Long Piao.

  Mass spectrometry imaging (MSI)-based spatial metabolomics exhibits extensive missing values; yet, practical guidance on how imputation choices affect both imputation accuracy and downstream spatial analyses remains limited. In this study, we evaluated eight imputation methods, including both existing approaches and a graph convolutional network (GCN)-based method specifically designed for spatial metabolomics data, to identify suitable approaches for spatial metabolomics. To enable comprehensive assessment, we developed an evaluation framework focusing on two objective criteria: (a) imputation accuracy and (b) preservation of spatial cluster structure. We assembled six benchmark datasets spanning mouse brain and liver, human kidney and stomach, and plant seed sections, and conducted controlled dropout simulations of missing values. Across both evaluation dimensions, including imputation accuracy and preservation of spatial cluster structure, RF ranked first overall, and GCN ranked second in both dimensions. Overall, this systematic, dual-perspective benchmark study provides guidance for selecting imputation strategies in spatial metabolomics research.

Keywords:  bioinformatics; machine learning; metabolomics; omics

DOI:  https://doi.org/10.1016/j.isci.2026.115203
STAR Protoc. 2026 Mar 22. pii: S2666-1667(26)00112-7. [Epub ahead of print]7(2): 104459

Protocol to purify fatty acid metabolites with two approaches for quantification using liquid chromatography-mass spectrometry.

Tomomi Hashidate-Yoshida, Masaki Yamada, Katsuyuki Nagata, Yasuyuki Kihara, Yoshihiro Kita, Hideo Shindou.

  Fatty acid metabolites, such as eicosanoids and docosanoids, play important biological roles and are strictly regulated by diverse enzymes. Here, we present two approaches for purifying their metabolites, including the phospholipid mediator platelet-activating factor (PAF), for quantification using liquid chromatography-mass spectrometry (LC-MS). We describe steps for tissue collection, lipid extraction, and lipid mediator purification. We then detail procedures for data analysis. This protocol allows the selection of a suitable technique for analyzing target molecules. For complete details on the use and execution of this protocol, please refer to Yamamoto et al.1.

Keywords:  Cell Membrane; Health Sciences; Metabolism; Signal Transduction

DOI:  https://doi.org/10.1016/j.xpro.2026.104459
Biosensors (Basel). 2026 Mar 04. pii: 147. [Epub ahead of print]16(3):

A Minimally Invasive LC-MS/MS Approach for Assessing Endocannabinoids in Saliva and Capillary Blood Microsamples.

Jessica Hargreaves, Gabrielle Eddes, David S Nichols, Luke J Ney.

  N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG) are lipid signalling molecules within the endocannabinoid system, which regulates numerous physiological processes and is implicated in diverse pathological conditions. Given the limited feasibility of obtaining human tissue samples, quantifying AEA and 2-AG in biological matrices is essential for understanding the endocannabinoid system in humans. While many studies have used blood samples for this purpose, the collection of this matrix typically requires invasive venipuncture, which limits the scalability and practicality of endocannabinoid research. This study validated extraction and LC-MS/MS methods for quantifying AEA and 2-AG (co-quantified with its isomer 1-AG) in minimally invasive matrices, including saliva and finger-prick blood microsamples, with acceptable linearity, recovery, reproducibility, and matrix effects. The assay additionally enabled exploratory quantification of arachidonic acid, oleoylethanolamide (OEA), palmitoylethanolamide (PEA), and selected steroid hormones, supporting multiplexed assessment from a single sample. Analyte concentrations measured in blood microsamples did not directly correspond to plasma concentrations, indicating that microsampling is suited for assessing relative within-study changes rather than absolute plasma equivalence. Application of the method demonstrated that venipuncture did not significantly alter salivary AEA or 2-AG concentrations. Overall, this method provides a minimally invasive and accessible approach for investigating endocannabinoid dynamics alongside other physiological biomarkers.

Keywords:  2-arachidonoylglycerol; LC–MS/MS; N-arachidonoylethanolamine; endocannabinoids; finger-prick blood; lipid signalling; method validation; microsampling; minimally invasive sampling; saliva

DOI:  https://doi.org/10.3390/bios16030147
J Chromatogr B Analyt Technol Biomed Life Sci. 2026 Mar 12. pii: S1570-0232(26)00111-X. [Epub ahead of print]1276 125022

Chromatography and mass spectrometry in therapeutic drug monitoring: Method performance, practical trade-offs, and implementation considerations.

Ibrahim Choucair.

  Therapeutic drug monitoring (TDM) is an essential clinical tool to individualize dosing for medications with narrow therapeutic indices or highly variable pharmacokinetics. This review provides a comprehensive overview of chromatography and mass spectrometry-based methodologies for TDM, focusing on their application to antibiotics (especially β-lactams), immunosuppressants, antifungals, and antiepileptic drugs in adult, pediatric, and intensive care settings. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has emerged as the gold-standard analytical technique for many TDM assays due to its superior sensitivity and specificity. LC-MS/MS methods enable simultaneous quantification of multiple drugs with minimal interference, which is particularly advantageous for patients on multi-drug regimens. Conventional chromatographic methods (HPLC with UV or fluorescence detection) remain in use as cost-effective alternatives for certain high-concentration drugs, while automated immunoassays are widely used for their high throughput and ease of use despite issues of cross-reactivity and limited availability for newer drugs. We compare the analytical performance of these methodologies, including sensitivity, specificity, accuracy and precision, matrix effects, and sample throughput. We also discuss practical aspects of clinical implementation: instrument and reagent costs, requirement for specialized personnel and validation and operational challenges such as turnaround time in critical care. In conclusion, chromatography and mass spectrometry techniques offer unparalleled analytical performance for TDM, addressing limitations of immunoassays and enabling precise drug management in complex clinical scenarios. This review underscores the importance of these methods in optimizing therapy for critical drug classes and highlights the ongoing innovations bridging the gap between research laboratories and real-world clinical practice.

Keywords:  Analytical validation; Antiepileptic drugs; Antifungal agents; Beta-lactam antibiotics; Immunosuppressants; LC-MS/MS; Therapeutic drug monitoring (TDM)

DOI:  https://doi.org/10.1016/j.jchromb.2026.125022
Drug Des Devel Ther. 2026 ;20 537699

Simultaneous Determination of Venetoclax and Posaconazole in Human Plasma by UPLC-MS/MS: Application to Therapeutic Drug Monitoring in Acute Myeloid Leukemia Patients.

Xiaohai Chen, Hualu Wu, Haoxin Fu, Peiqi Wang, Lu Cao, Ruibin Li, Ruanjuan Zhan, Ren-Ai Xu.

   Background: Due to the high risk of invasive fungal disease (IFD) in acute myeloid leukemia (AML) patients, the antifungal drug posaconazole is often co-administered with venetoclax. As posaconazole is a potent inhibitor of CYP3A4, the standard dosing regimen may lead to the elevated plasma concentrations of venetoclax due to potential drug-drug interactions (DDIs). Therefore, therapeutic drug monitoring (TDM) is necessary to optimize the dosage.
Methods: This study developed and validated a rapid and sensitive ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous quantification of venetoclax and posaconazole in human plasma. Plasma samples were pretreated using acetonitrile precipitation. The chromatographic separation was achieved using an Acquity BEH C18 column with gradient elution. The mobile phase consisted of 0.1% formic acid in water and acetonitrile, with a flow rate of 0.4 mL/min.
Results: The method demonstrated good sensitivity and linearity within the concentration ranges of 10-15,000 ng/mL for venetoclax and 10-10,000 ng/mL for posaconazole, respectively. Additionally, the method showed acceptable selectivity, intra-day precision, inter-day precision, accuracy, matrix effects (95.2% to 102.0% for venetoclax and 98.4% to 102.5% for posaconazole), extraction recovery (93.2% to 95.4% for venetoclax and 87.8% to 95.8% for posaconazole), and stability under various conditions. The trough concentrations of venetoclax were 9326.88 ± 12,169.05 ng/mL in patients treated with venetoclax alone, and 31,623.55 ± 28,453.67 ng/mL in patients treated with venetoclax in combination with posaconazole.
Conclusion: A rapid and simple method was established and successfully applied to the simultaneous determination of the concentrations of venetoclax and posaconazole in AML patients, providing a basis for TDM and clinical pharmacokinetic analysis of these drugs in AML patients.

Keywords:  UPLC-MS/MS; acute myeloid leukemia; invasive fungal disease; therapeutic drug monitoring

DOI:  https://doi.org/10.2147/DDDT.S537699
Int J Mol Sci. 2026 Mar 13. pii: 2624. [Epub ahead of print]27(6):

Enhanced Untargeted Metabolomics Based on High-Resolution Mass Spectrometry Reveals Global Rewiring Due to Mitochondrial Dysfunction in Yeast.

Fabrizio Mastrorocco, Luca De Martino, Igor Fochi, Graziano Pesole, Ernesto Picardi, Clara Musicco, Sergio Giannattasio.

  Mitochondrial dysfunction profoundly alters cellular metabolism, yet its systems-level consequences remain incompletely characterized. Here, we present a comprehensive untargeted metabolomics analysis of respiratory-deficient (ρ0) and competent (ρ+) Saccharomyces cerevisiae prototrophic cells using ultra-high-performance liquid chromatography coupled to Orbitrap Fusion™ Tribrid™ high-resolution mass spectrometry. By integrating hydrophilic interaction and reversed-phase chromatography in both ionization modes, we detected ~7000 features per chromatographic condition, of which ~12% were structurally annotated through MSn fragmentation and in silico spectral matching. Principal component analysis revealed distinct metabolic signatures between ρ0 and ρ+ cells, with ~73% of total variance explained by the first two components. Volcano plot and hierarchical clustering analyses identified a marked accumulation of phosphate-containing metabolites, sphingolipids, ceramides, and fatty acid residues in ρ0 cells, whereas amino acids, excluding arginine, cysteine, and aromatics, were enriched in ρ+ cells. Notably, branched-chain amino acid depletion in ρ0 cells correlated with impaired growth and mitochondrial stress. Pathway enrichment analysis, supported by transcriptomic integration, prompted us to further investigate reprogramming of polyamine biosynthesis and aromatic amino acid metabolism. Calibration curves constructed from certified standards validated the accuracy of the LC-MS platform and reinforced annotation confidence. Our findings demonstrate that advanced untargeted metabolomics, coupled with MS3 fragmentation and multi-omics integration, enables high-resolution mapping of metabolic reconfiguration under mitochondrial dysfunction, offering mechanistic insights into mitochondrial retrograde signaling and adaptation.

Keywords:  mass spectrometry; metabolite annotation; mitochondrial dysfunction; mitochondrial retrograde pathway; untargeted metabolomics; yeast

DOI:  https://doi.org/10.3390/ijms27062624
Front Public Health. 2026 ;14 1775284

AI redefine untargeted metabolomics: estimating chemical amounts for a Human Exposome Project.

Fenna C M Sillé, Karolina Kopańska, Carsten Prasse, Thomas Luechtefeld, Thomas Hartung.

  The Human Exposome Project aims to map the totality of environmental exposures, but its success relies on transforming qualitative detections into quantitative data. Following our review on AI-driven metabolite identification, this second installment addresses the next critical bottleneck: estimating chemical concentrations in untargeted metabolomics without authentic standards. Translating LC-HRMS signal intensities into absolute concentrations is hindered by the vast variability in ionization efficiency and matrix effects, particularly for xenobiotics where reference standards are unavailable. We review emerging strategies that leverage artificial intelligence-ranging from descriptor-based regression to deep learning on molecular point clouds-to predict ionization response factors. We further evaluate a "matrix-embedded" calibration approach that utilizes ubiquitous endogenous metabolites (e.g., amino acids, lipids) as internal anchors to normalize response scales across studies. These innovations enable "tiered semi-quantification," allowing the classification of exposures into biologically relevant ranges (e.g., nanomolar vs. micromolar). This stratification facilitates direct integration with toxicological frameworks, such as the Threshold of Toxicological Concern (TTC) and high-throughput bioactivity data (e.g., ToxCast), for rapid risk prioritization. By integrating quantitative AI prediction models with robust quality assurance, untargeted metabolomics can evolve from a qualitative discovery tool into a quantitative engine for exposure science, providing the necessary evidence to link complex chemical exposures to human health outcomes.

Keywords:  Human Exposome Project; Threshold of Toxicological Concern (TTC); artificial intelligence; concentration prediction; exposomics; ionization efficiency; quantitative structure–retention relationships; untargeted metabolomics

DOI:  https://doi.org/10.3389/fpubh.2026.1775284
Molecules. 2026 Mar 16. pii: 1001. [Epub ahead of print]31(6):

Development and Validation of SEC-UV/HRMS Procedure for Simultaneous Determination of BSA and Its Association Products.

Blaž Hodnik, Žiga Čamič, Matevž Pompe.

  Monitoring peptide and protein self-association is essential for understanding biological function, formulation stability, and aggregation mechanisms. While size-exclusion chromatography (SEC) is routinely used to quantify protein-size variants under native conditions, its hyphenation to high-resolution mass spectrometry (HRMS) for simultaneous structural characterization remains limited. Here, we report the development and validation of a robust SEC-UV/HRMS method optimized for native-like analysis of bovine serum albumin (BSA) monomers and higher-order oligomers using standard-flow electrospray ionization. Systematic evaluation of source parameters, mobile-phase composition, and chromatographic conditions enabled retention of native BSA structure, minimized in-source unfolding, and enhanced MS sensitivity, allowing detection of oligomers up to the heptamer. A short, narrow-bore 200 Å UHPLC SEC separation column was used. Low-flow separations (~0.05 mL/min) enabled efficient ionization and 10 min run times. An accelerated 60 °C stress-testing protocol demonstrated that SEC-MS can semi-quantitatively monitor oligomerization dynamics, complementing UV-based quantification and revealing transient species not resolved by UV alone. The method showed acceptable linearity, precision, and sample stability, and comparison with SEC-RALS/LALS confirmed molecular-weight trends across aggregation states. Overall, the developed SEC-UV/HRMS workflow provides a rapid, sensitive, and widely accessible approach for UV-based quantification of monomer- and HRMS-based characterizing protein aggregation in research and quality control in pharmaceutical laboratories.

Keywords:  high-resolution mass spectrometry; proteins; size exclusion chromatography

DOI:  https://doi.org/10.3390/molecules31061001
Biomedicines. 2026 Mar 11. pii: 632. [Epub ahead of print]14(3):

S-Adenosylmethionine (SAM) and S-Adenosylhomocysteine (SAH) Monitoring Using Analytical Methods in Clinical Laboratory Practice: Where Are We?

Antonina Kuty, Arkadiusz Kocur, Bartosz Molasy, Małgorzata Wrzosek.

  S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) are essential intermediates in one-carbon metabolism and key regulators of cellular methylation capacity. Their concentrations and the SAM/SAH ratio are increasingly studied as biomarkers across metabolic, cardiovascular, neurological, and cancer-related diseases. This review outlines validated analytical methods for quantifying SAM and SAH, focusing primarily on liquid chromatography-tandem mass spectrometry (LC-MS/MS), which is considered the gold standard in both clinical and research settings. A comprehensive literature search identified studies on method development, validation, and clinical use of SAM and SAH measurements. Special attention is given to analytical challenges arising from their high polarity, structural similarity, endogenous presence, and limited stability. The review also discusses preanalytical variables, including biological matrix selection, sample handling, and storage conditions. LC-MS/MS methods are compared with alternative techniques, such as immunoassays, with respect to sensitivity, specificity, matrix effects, and clinical relevance. Additionally, the review summarizes the concentration ranges of SAM and SAH, and their ratio, in healthy and patient populations, noting current standardization limitations. Overall, the review highlights the importance of harmonized analytical protocols and matrix-specific validation to enable reliable clinical interpretation of SAM and SAH as methylation biomarkers.

Keywords:  SAH; SAM; one-carbon metabolism

DOI:  https://doi.org/10.3390/biomedicines14030632
Planta. 2026 Mar 24. pii: 113. [Epub ahead of print]263(5):

Future perspectives in mass spectrometry of plant lipids.

Katharina Gutbrod, Peter Dörmann.

   MAIN CONCLUSION: Important topics of plant lipidomic research include the standardization of protocols for quantification, and the analysis of subcellular distribution of common and unusual lipids, both in Arabidopsis and non-model species. Plant lipid research has seen a tremendous progress in the last decades, particularly in the area of lipid analytics by mass spectrometry. This includes the characterization of the different lipid classes involved in the establishment of the membrane bilayer, in carbon storage, and signaling. Advances in mass spectrometry have transformed the landscape of plant lipid research, enabling large scale studies of complex lipids at the level of individual molecular species, with minimal efforts of sample preparation. Lipidomic technologies employ targeted approaches to analyze known lipid molecular species as well as non-targeted methods to identify lipids that accumulate differentially in specific sample sets. Lipid quantification requires the availability of appropriate standards and highly sensitive methods of mass spectrometry. Additional technologies have been developed to study the spatial distribution of lipids in plant tissues, as well as to identify and characterize unusual lipids in plant cells. Finally, the large amounts of data generated in plant lipid research require sophisticated databases that connect the 'omics' data with data on growth, development, and adaptive responses to stress conditions at the tissue, cellular, and subcellular levels.

Keywords:  Biosynthesis; Lipidomics; Mass spectrometry; Organelle; Subcellular distribution; Transport

DOI:  https://doi.org/10.1007/s00425-026-04981-5
Analyst. 2026 Mar 26.

Dielectric barrier discharge ionization (DBDI) enables rapid analysis of new psychoactive substances with ion mobility-mass spectrometry.

Bradley B Garrison, Copeland R Johnson, Ralph Aderorho, Christopher D Chouinard.

New psychoactive substances (NPS) present a major public health crisis across the world due to their variable potency, constant evolution within the recreational drug community, and ability to skirt legal/policy regulations. Because of the frequency with which new substances are introduced, it is increasingly difficult for clinical, toxicological, and forensic laboratories to keep up with the newest drug threats, presenting a critical need for development of rapid analytical methods capable of confident structural characterization. In the present work, we demonstrate successful coupling of a commercial dielectric barrier discharge ionization (DBDI) source to two ion mobility-mass spectrometry (IM-MS) instruments, including high-resolution Structures for Lossless Ion Manipulations (SLIM). The DBDI source enables rapid introduction of NPS which can subsequently be characterized by IM-MS. Specifically, we show that IM can be used to differentiate structural isomers of synthetic cannabinoids, benzodiazepines, nitazenes, and fentanyl analogues with very minor differences in their collision cross sections (CCS). We also note that the mobility spectra for those compounds presenting protonation site isomers ("protomers") differed from previous work on electrospray ionization (ESI)-generated species from our group and others; this observation is not unsurprising given the different fundamental mechanism of DBD ionization and warrants future interrogation. Finally, we demonstrate the combination of ion mobility with tandem mass spectrometry (MS/MS) for mobility-aligned fragmentation that provided additional structural information for confident characterization. The coupling of DBDI with IM-MS/MS (especially high-resolution IM) constitutes a powerful approach for rapid analysis of several classes of NPS that could be used to improve throughput in the future.

DOI: https://doi.org/10.1039/d6an00028b
Anal Chem. 2026 Mar 26.

Unified Multitask Modeling for Retention Time Prediction Across Chromatographic Conditions.

Ziyao Xiong, Xujie Wang, Junqi Liu, Shan Cong, Qiong Yang, Hongchao Ji.

Retention time (RT) is a key parameter in liquid chromatography-mass spectrometry (LC-MS) workflows, supporting compound identification, feature alignment, and quality control. However, traditional RT prediction models are built for specific chromatographic conditions, resulting in fragmented knowledge and limited scalability. We introduce Uni-RT, a unified multitask learning framework that simultaneously learns from heterogeneous data sets to capture both shared molecular retention patterns and condition-specific differences. By leveraging data across multiple chromatographic setups, Uni-RT achieves higher accuracy and robustness than pooled or condition-specific models while greatly simplifying model deployment. Evaluation on 28 reversed-phase liquid chromatography (RPLC) and hydrophilic interaction liquid chromatography (HILIC) data sets demonstrates that multitask learning provides a powerful and generalizable solution for integrating RT prediction into diverse applications.

DOI: https://doi.org/10.1021/acs.analchem.5c07973
Biomed Chromatogr. 2026 May;40(5): e70434

Pharmacokinetics, Bioavailability, and Metabolism of Zongertinib, a Novel HER2-Selective Tyrosine Kinase Inhibitor, in Rat by Liquid Chromatography Hyphenated With Electrospray Ionization Tandem Mass Spectrometry.

Wenfei Sun, Fang Wang, Furui Chu, Zheheng Ma.

  Zongertinib, a selective human epidermal growth factor receptor 2 (HER2) tyrosine kinase inhibitor, has been approved by the US Food and Drug Administration for the treatment of non-small cell lung cancer. This study aimed to develop a sensitive and cost-effective LC-MS/MS method for quantifying zongertinib in rat plasma. Following protein precipitation with acetonitrile, samples were analyzed on an ACQUITY BEH C18 column using a gradient of 0.1% formic acid and acetonitrile at 40°C within a 2-min run time. The assay demonstrated excellent linearity from 1 to 1000 ng/mL (r > 0.995). All validation parameters-including precision, accuracy, matrix effect, recovery, and stability-met accepted criteria for bioanalytical quantification. The validated method was successfully applied to a pharmacokinetic study in rats. Additionally, metabolites in rat plasma were investigated using LC-Orbitrap-HRMS. Three metabolites were identified and structurally characterized based on accurate mass and fragmentation patterns, revealing metabolic pathways such as oxygenation, demethylation, and epoxide hydrolysis. This is the first report on the method validation for the measurement of zongertinib in biological matrices, which enables clinical development of zongertinib and can be applied for clinical pharmacokinetics and therapeutic drug monitoring in future clinical practice.

Keywords:  LC–MS/MS; Zongertinib; bioavailability; metabolism; pharmacokinetics

DOI:  https://doi.org/10.1002/bmc.70434
Diagnostics (Basel). 2026 Mar 19. pii: 911. [Epub ahead of print]16(6):

Fully Automated Serum LC-MS/MS Platform and Pediatric Reference Intervals for Organic Acids, Amino Acids, and Acylcarnitines in Children (Ages 0-6 Years): Toward Quantitative Diagnosis of Inborn Errors of Metabolism.

Yasushi Ueyanagi, Daiki Setoyama, Tsuyoshi Nakanishi, Yuichi Mushimoto, Vlad Tocan, Hironori Kobayashi, Miki Matsui, Shinya Matsumoto, Akiyoshi Fujishima, Taeko Hotta, Ayumi Sakata, Yuya Kunisaki.

  Background/Objectives: Conventional diagnosis of inborn errors of metabolism (IEMs) requires multiple specimen types-urine organic acids, plasma amino acids, and serum acylcarnitines-analyzed on distinct analytical platforms. This multi-assay approach is labor-intensive and limits timely clinical decision making. We aimed to develop a fully automated serum-based LC-MS/MS platform for integrated quantitative metabolite profiling and to establish pediatric reference intervals (RIs) to support diagnostic interpretation. Methods: A fully automated LC-MS/MS system integrated with the CLAM-2030 automated pretreatment module was developed to enable simultaneous quantification of 25 organic acids, 8 amino acids, and 21 acylcarnitines. Analytical performance was assessed for linearity, limits of detection and quantification, precision and accuracy. Serum samples from 296 non-IEM children aged 0-6 years were analyzed to establish pediatric RIs using Box-Cox transformation and Gaussian modeling. Clinical utility was evaluated in sera from 89 patients diagnosed with IEM using z-score-based logistic regression models. Results: The method demonstrated excellent performance, with linearity (r2 > 0.99) across calibration ranges, limits of detection and quantification defined by signal-to-noise ratios > 3 and >10, and intra- and inter-assay precision < 15% CV for all 54 analytes. Twenty-one analytes met the acceptance criterion of ±20% accuracy at all quality-control levels. Pediatric RIs provided a quantitative framework for interpreting the metabolic abnormalities. In IEM patients, disease-specific metabolites were consistently outside the established ranges, and z-score-based logistic regression models successfully distinguished major IEM categories, including organic acidemias and long-chain fatty acid oxidation disorders. Conclusions: This fully automated, serum-based LC-MS/MS platform provides a clinically practical and quantitative framework for integrated metabolic profiling using pediatric RIs, supporting diagnosis and monitoring of IEMs in pediatric settings.

Keywords:  acylcarnitines; amino acids; inborn errors of metabolism (IEMs); liquid chromatography–tandem mass spectrometry (LC–MS/MS); organic acids; pediatric reference intervals

DOI:  https://doi.org/10.3390/diagnostics16060911
Toxins (Basel). 2026 Mar 06. pii: 132. [Epub ahead of print]18(3):

Simultaneous Determination of Multiclass Cyanotoxins in Aquatic Products, Vegetables and Algal Dietary Supplements Using Dispersive Solid-Phase Extraction (dSPE)-UHPLC-MS/MS.

Baiyu Lai, Guanxiang Yuan, Qing Luo, Xiaoyun Qin, Zhaoying Lv, Haojia Ma, Huiling Chen, Honghe Liu, Guihua Liu, Jie Jiang.

  Cyanotoxins, prevalent in eutrophic aquatic ecosystems, pose significant health risks via contaminated food, yet analytical methods for detecting multiple toxin classes in foodstuffs remain limited. In the current study, a method based on dispersive solid-phase extraction (dSPE) coupled with ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed to simultaneously determine four common classes of cyanotoxins (i.e., microcystins, cylindrospermopsins, nodularins, and anatoxins) in aquatic products, vegetables and algal dietary supplements. Following initial extraction with 80% aqueous methanol, sample purification was performed using anhydrous sodium sulfate (400 mg) and C18 sorbent (50 mg). For plant-based foods, additional graphitized carbon black (GCB, 15 mg) was also included. The method was successfully validated in eight different food matrices, demonstrating recoveries of 65-122% and relative standard deviations below 19%. The limits of detection and quantification across all matrices ranged from 0.1 to 3.4 μg/kg dry weight (dw) and 0.4 to 11.4 μg/kg dw, respectively. When applied to 96 food samples, this method detected multiple cyanotoxins in Tilapia and Spirulina-based dietary supplements. The proposed method provides a rapid, cost-effective, high-throughput, and sensitive analytical tool suitable for monitoring multiple cyanotoxins in various foodstuffs.

Keywords:  cyanotoxin; cylindrospermopsin; dispersive solid-phase extraction; foodstuff; microcystins

DOI:  https://doi.org/10.3390/toxins18030132
Toxins (Basel). 2026 Mar 10. pii: 135. [Epub ahead of print]18(3):

Matrix Effect Variability in Urine Samples from Different Cohorts and Implications on LC-ESI-MS Mycotoxin Biomarker Analysis.

Michael Kuhn, Åsa Svanström, Nicholas N A Kyei, Sanna Lignell, Hans-Ulrich Humpf, Benedikt Cramer.

  Matrix effects (ME) during LC-ESI-MS analysis are a commonly acknowledged issue for a variety of matrices and analytes. Although sample preparation techniques are steadily evolving to reduce ME, the complexity and variability of the urine matrix remain a challenge, especially for multi-analyte methods. To investigate the extent of ME implications on method performance and quantification, we used stable isotope-labelled standards (SIL-IS) of 11 mycotoxins to evaluate the magnitude and variability of ME in urine samples from two cohorts: Bangladeshi adult women (n = 50) and Swedish children of both sexes (n = 340). Significant ME differences were observed between the two cohorts for eight of the 11 mycotoxins. Additionally, intra-cohort ME variability turned out to be very high with interquartile ranges (IQR) above 15% for 14 out of 22 analyte-cohort combinations. Maximum IQR values were observed for sterigmatocystin in the Bangladeshi cohort (318%), strongly impacting quantitative results obtained with matrix(-matched) calibration. Further experiments on a small German cohort of four subjects, each providing four to five urine samples, revealed high variability of ME within each individual. Factors influencing ME were investigated, showing little to no impact of sex and a moderate impact of age for some analytes in the Swedish cohort. Nonetheless, especially the more polar analytes, showing stronger signal suppression, demonstrated clear correlation of ME with density and creatinine concentration of the urine samples. As a result, urine samples with very high or low density or creatinine values require careful handling in regard to sensitivity or quantification errors when matrix(-matched) calibration without SIL-IS is applied.

Keywords:  LC-MS/MS; biomonitoring; matrix effect; mycotoxin biomarkers; urine samples

DOI:  https://doi.org/10.3390/toxins18030135
Anal Bioanal Chem. 2026 Mar 27.

Comprehensive profiling of arsenosugars in algae using UHPLC-HRMS and UHPLC-IMS-Q-TOF.

Alba Morales-Rodríguez, Àngels Sahuquillo, José Fermín López-Sánchez, Dolores Barrón, Encarnación Moyano.

  Arsenic is a ubiquitous environmental contaminant, and its toxicological impact is highly dependent on its speciation. In marine edible algae, increasingly consumed for their nutritional value, arsenosugars (As-Sugars) constitute the major arsenic forms. Despite their generally low toxicity, their uncertain long-term effects make accurate identification essential. We developed an analytical workflow combining ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS). Both Q-Orbitrap and IMS-Q-TOF systems were employed, operating in positive and negative electrospray ionization (ESI) modes. Using a zwitterionic hydrophilic interaction liquid chromatography (HILIC-Z) column, we achieved effective separation of the target compounds and subsequently performed detailed HRMS and MS/MS analyses. This approach enabled the structural annotation of four key As-Sugars (Gly-Sug, PO4-Sug, SO3-Sug, and SO4-Sug) on the basis of accurate mass measurements and diagnostic fragmentation patterns. Notably, we report for the first time the collision cross-section (CCS) values of these As-Sugars, providing an additional orthogonal parameter that strengthens their confirmation.

Keywords:  Algae; Arsenosugars; HILIC; HRMS; Ion mobility

DOI:  https://doi.org/10.1007/s00216-026-06454-w
Environ Monit Assess. 2026 Mar 25. pii: 350. [Epub ahead of print]198(4):

Environmental occurrence of amantadine and rimantadine in aquaculture pond sediments: application of a newly developed LC-MS/MS method.

Xin Zhou, Shan Cui, Xuesong Wang, Xinyu Guo, Bin Qu, Meirong Zhao, Yan Zeng, Qiang Hou.

  The presence of antiviral drugs in aquaculture systems has received increasing attention due to their potential environmental implications. In this study, a sensitive and reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established and validated for the simultaneous determination of amantadine (AMT) and rimantadine (RMT) in aquaculture pond sediments. The method showed excellent linearity (R2 > 0.9990) over the tested concentration range, with limits of detection and quantification of 0.5 μg/kg and 1.0 μg/kg, respectively. Satisfactory recovery (91.2~104.8%) and good precision were obtained at different spiking levels, confirming the suitability of the method for complex sediment matrices. Sediment samples were collected from 10 aquaculture ponds, including 5 intensive and 5 semi-intensive systems. AMT and RMT were detected in 80% and 60% of the samples, respectively. Concentrations of AMT ranged from 1.2 to 6.5 μg/kg, while RMT concentrations ranged from 0.9 to 4.2 μg/kg. Notably, residue content in sediments from intensive systems was consistently higher than those from semi-intensive systems, suggesting that management practices and drug input intensity strongly influence the accumulation of antiviral drug residues in sediments. These findings indicate that aquaculture sediments act as a significant environmental sink for veterinary pharmaceuticals, with potential ecological and food safety implications. Residues of AMT and RMT in sediments may be re-mobilized into the water column, bioaccumulate in aquatic organisms, and ultimately drive the development of drug resistance. The validated method provides a robust tool for routine environmental monitoring and contributes baseline data on the occurrence of AMT and RMT in aquaculture systems. Overall, this research underscores the need for stricter drug management policies, improved aquaculture practices, and further studies on the long-term environmental fate and risks of antiviral residues in aquatic ecosystems.

Keywords:  Antiviral agents; Aquaculture sediments; Environmental monitoring; Residue accumulation

DOI:  https://doi.org/10.1007/s10661-026-15223-2
Foods. 2026 Mar 10. pii: 981. [Epub ahead of print]15(6):

Quantification of Macular Carotenoids over a Wide Dynamic Range in Plant Matrices and Caco-2 Cells Using a Single Transferable Analytical Method.

Jenani Sutharsan, Lewis Adler, Alison Jones, Jayashree Arcot.

  Lutein and zeaxanthin are macular carotenoids known for their protective role against major eye diseases. The bio-accessibility of these macular carotenoids is extremely low, with a limited amount synthesised in plants. Quantifying these compounds in plants/biological samples is challenging because of their structural similarity. Although numerous methods have been reported for quantifying macular carotenoids, there is currently no unified chromatographic technique that can be applied for the separation and quantification of these carotenoids across diverse matrices over a broad dynamic range while also incorporating an effective extraction step. Biochemical processes during digestion and absorption further lower carotenoid levels in the body (bioavailability), making precise measurement of their esterified forms necessary. Here, we incorporate an alkaline hydrolysis extraction and present a single liquid chromatographic method applicable to both PDA and MS detection for the separation and quantification of lutein and zeaxanthin across various matrices (food, digesta, and Caco-2 cells) and concentration ranges. It utilises common solvents for the mobile phase system and a C30 column. The reverse-phase method achieved excellent recoveries in spiked samples, acceptable relative standard deviations (RSDs) for validation parameters, and offers potential for high-throughput analysis while being transferable between matrices (from plant to Caco-2 cells).

Keywords:  Caco-2 cells; bio-accessibility; in vitro digestion; liquid chromatography; lutein; zeaxanthin

DOI:  https://doi.org/10.3390/foods15060981
J Agric Food Chem. 2026 Mar 26.

Single Laboratory Validation of a Liquid Chromatography-Tandem Mass Spectrometry Method for the Quantitation of Microcystins in Marine and Estuarine Shellfish.

I-Shuo Huang, Mary Dawn Celiz, John C Bowers, Jonathan R Deeds.

  Several reports have shown that the freshwater cyanobacterial toxins microcystins (MCs) can be transported along the freshwater to marine continuum and can be found in edible marine and estuarine shellfish. However, data for shellfish from commercial harvesting areas is limited. To further assess the concentrations found in these vectors and the risks that they pose to consumers, a validated analytical method is required. Herein, a liquid chromatography-tandem mass spectrometry-based method for the detection of eight MCs (MC-LA, -LF, -LR, -LW, -LY, -RR, -YR, and nodularin-R) was single laboratory validated in Eastern oysters (Crassostrea virginica), blue mussels (Mytilus edulis), hard clams (Mercenaria mercenaria), and softshell clams (Mya arenaria). Median recoveries for all four matrices ranged from 85.3 to 101.0% with RSDs between 3.5 and 14.3%. Overall, the method was found to be accurate, precise, and specific over an extended range of 10-500 μg/kg and determined to be fit for purpose for the screening of MCs in the shellfish matrices tested.

Keywords:  LC-MS validated method; clams; microcystin; oysters; shellfish

DOI:  https://doi.org/10.1021/acs.jafc.5c04528
J Chromatogr A. 2026 Mar 05. pii: S0021-9673(26)00195-0. [Epub ahead of print]1775 466865

Characterization of siRNA product-related impurities by hydrophilic interaction liquid chromatography (HILIC) coupled with mass spectrometry.

Micaela Graglia, Sean Brian Yeldell, Nadeschda Demtschenko, Lucas Bethge.

  Quality control of therapeutic oligonucleotides is mainly achieved by Ion-Pair Reversed Phase Liquid Chromatography (IP-RPLC) coupled to Mass Spectrometry and Anion-Exchange Liquid Chromatography. As manufacturing requirements increase during clinical development, so too do the requirements for the separation of impurities from full-length product. Hence, there is a need for a wider range of analytical methods for therapeutic oligonucleotides. Hydrophilic Interaction Liquid Chromatography (HILIC) is emerging as an orthogonal method for oligonucleotide analysis. We present an Ultra-Performance Liquid Chromatography Mass Spectrometry HILIC method with good separation of truncation impurities in modified RNA. We share an example where the method is applied to partly phosphorothioated single strands that are used to form GalNAc-conjugated double stranded siRNA. Truncation impurities arising from incomplete coupling were well separated from their parent FLP, both for incomplete couplings in the sequences as well as in the GalNAc-cluster, which is built up by successive couplings of a brancher and GalNAc phosphoramidite. The results showed both comparability of HILIC with IP-RPLC and orthogonality of HILIC towards IP-RPLC for the separation of GalNAc-cluster-related truncations.

Keywords:  GalNAc-conjugated siRNA; Hydrophilic interaction chromatography; Liquid chromatography; Product-related impurities

DOI:  https://doi.org/10.1016/j.chroma.2026.466865
Int J Mol Sci. 2026 Mar 20. pii: 2840. [Epub ahead of print]27(6):

Signals of Diagnostic Product Ions of Kavalactones in Their ESI Mass Spectra-Implications for Isomer Differentiation and Identification of Kavalactone Conjugates.

Małgorzata Kasperkowiak, Wojciech Jankowski, Marcin Hoffmann, Błażej Gierczyk, Rafał Frański.

  Kavalactones are psychoactive substances that naturally occur in some plants, such as Piper methysticum, Alpinia zerumbet, and Achyrocline satureioides, which are considered to have a significantly positive effect on human organisms. For example, Alpinia zerumbet is classified as a life-expanding plant. Although high-pressure liquid chromatography-mass spectrometry has been used for kavalactone analysis in plant material, the fragmentation pathways of protonated kavalactone molecules are not fully known and require further detailed study. In this paper, the fragmentation pathways of [M+H]+ ions of twelve kavalactones, including three pairs of isomers, are discussed in detail. Special emphasis has been placed on diagnostic product ions, which are characteristic of kavalactone structures. It has been demonstrated that diagnostic ions and structure-fragmentation relationships enable the differentiation of isomeric kavalactones and may be useful for the identification of other kavalactone conjugates, such as kavalactone dimers or kavalactone glycosides.

Keywords:  electrospray ionization; fragmentation pathways; isomer differentiation; kavalactones; tandem mass spectrometry; untargeted analysis

DOI:  https://doi.org/10.3390/ijms27062840