bims-metlip 2026-06-14 papers

bims-metlip

Biomed News

on Methods and protocols in metabolomics and lipidomics

Issue of 2026–06–14
thirty papers selected by
Sofia Costa, Matterworks

Tandem Mass Spectrometry Imaging of Low-Abundance Ether Phospholipids Guided by Bulk Lipidomics Analysis.
Rapid Determination of 13 Insecticides and Acaricides in Human Blood Using Dispersive Liquid-Liquid Microextraction Coupled With DART-MS/MS.
ToxBase: A Multidimensional ToxCast Reference Database for High-Throughput Human Exposome Analysis.
A Validated UPLC-MS/MS Assay for Isosakuranetin Determination in Rat Plasma and Its Application to Pharmacokinetics.
A Simple and Rapid HPLC-MS/MS Method for Quantification of 15,16-Dihydrotanshinone I in Plasma and the Application to Pharmacokinetic Study.
Quantification of Bullatine A and Bullatine B in Rat Plasma Using UPLC-MS/MS and Application to Pharmacokinetics.
Development and application of a simple LC-MS/MS method for therapeutic drug monitoring to guide colistin dosing in critically Ill patients.
Untargeted metabolomics suggests a trade-off between phenolamides and flavonoids in the pollen of Petunia hybrida with contrasting flower colours.
Differences among canine serum, plasma and urine metabolite profiles from samples that were collected at the same time.
A Standardized Metabolomics Protocol For Analyzing Exercise-Induced Metabolic Shifts In Elite Boxers By Liquid Chromatography-Mass Spectrometry.
An Optimized Sample Pretreatment Method Followed by a Validated LC-MS/MS Method for Quantifying 6-TG and 6-MMP Concentrations in Red Blood Cells for Therapeutic Drug Monitoring in Inflammatory Bowel Disease Patients Using Thiopurines.
Development and bioanalytical validation of a high-sensitivity LC-MS/MS assay for quantitative determination of sotagliflozin in rabbit plasma and its stability across controlled storage conditions.
Isocratic zwitterionic HILIC-ESI-MS method for assay of ropinirole and quantitation of degradation impurities in extended-release tablets.
MultiMS2: A curated multi-modal, multi-energy spectral library for metabolomics.
Untargeted and Targeted Cerebrospinal Fluid Neurometabolomics via Chromatography-Mass Spectrometry-Based Methods.
eMZed 3: flexible and interactive development of scalable LC-MS/MS data analysis workflows in python.
Development and Optimisation of an HPLC-MS/MS Workflow for Profiling Selenium and Sulphur Amino Acids in Soybean Leaves and Investigation of Se-S Metabolic Interactions.
Analysis of suzetrigine, a novel non-opioid pain medication, in whole blood and urine using liquid chromatography-tandem mass spectrometry.
Rapid and sensitive quantification of pemetrexed in human plasma by LC-MS/MS using a stable isotope-Labeled internal standard for therapeutic drug monitoring.
A Step-by-Step Protocol From METASPACE to Biological Interpretation.
The Language of Elution: Autoregressive Prediction of the Next Feature in Untargeted LC-HRMS Lipidomics.
Robust analytical methods for bis(monoacylglycero)phosphate profiling in health and disease.
A Robust and Universal LC-MS/MS Method for Determination of N-Nitrosodimethylamine in Pharmaceuticals Using a C30 Column.
From Sampling to Screening: A Review of Targeted and Non-Targeted PFAS Analysis in Environmental Samples.
Robust Metabolomics Data Normalization across Scales and Experimental Designs.
Chemical Profiling of Aboveground and Underground Parts of Pterocephalus hookeri by Integrated FBMN, Untargeted LC-MS Metabolomics, and PAD-DESI-MSI.
Comprehensive Metabolomic Analysis of Saliva Using SWATH-DIA Reveals Systemic Metabolic Adaptations to Exercise.
Suspected and Non-Targeted Screening of Non-Edible Substances in Food by UPLC-Q-TOF-MS.
Analysis of Taurine in Infant Formula and Adult Nutritionals by HILIC-MS/MS: Collaborative Study, AOAC Official Method 2022.03:2026, Final Action.
Medicinal Amazonian Oleoresins: An Eco-Friendly Chemical Fingerprinting Method.

Anal Chem. 2026 Jun 12.

Tandem Mass Spectrometry Imaging of Low-Abundance Ether Phospholipids Guided by Bulk Lipidomics Analysis.

Tommy Zhang, Sara Amer, Julia Laskin.

A central challenge in mass spectrometry imaging (MSI) of lipids is detecting and identifying species overshadowed by higher abundance isobaric lipids. Although tandem mass spectrometry can differentiate many lipid isobars and some isomers, the diversity and heterogeneity of lipids observed in MSI experiments necessitate the development of targeted approaches to differentiate and localize species with an overlapping m/z. To address this challenge, we leverage the fast acquisition speed of multiple reaction monitoring (MRM) to identify and localize hundreds of lipids in a single MSI experiment. We present a workflow to generate comprehensive, system-specific, and information-rich MRM transition lists for MSI and use them to examine the spatial localization of specific lipid classes with nanospray desorption electrospray ionization (nano-DESI) MSI in MRM mode. The lists are generated by integrating information from the LIPID MAPS database with data-dependent acquisition (DDA) and filtering by examining MRM signals of the corresponding tissue lipid extract. Using 165 MRM transitions in a single nano-DESI MSI experiment, we examined the localization of plasmalogen species, their isomers, and corresponding isobars in mouse brain tissue with sn-chain-level annotation. This workflow, which can be readily adapted to other lipid classes and tissue types, establishes MRM-MSI as a powerful strategy for mapping lipid targets in complex tissues.

DOI: https://doi.org/10.1021/acs.analchem.6c01209
J Mass Spectrom. 2026 Jul;61(7): e70070

Rapid Determination of 13 Insecticides and Acaricides in Human Blood Using Dispersive Liquid-Liquid Microextraction Coupled With DART-MS/MS.

Yuan Zhou, Ke Hu, Xiaolong Hou, Chenyu Xue, Wenfang Zhang, Ying Zhang, Hua Liu.

  A high-throughput, solvent-minimized analytical method was developed by coupling dispersive liquid-liquid microextraction (DLLME) with direct analysis in real-time tandem mass spectrometry (DART-MS/MS) for the simultaneous quantification of multiple insecticides and acaricides in human blood. This method obviates the need for chromatographic separation, substantially reducing total analysis time. Extraction conditions were systematically optimized to achieve efficient enrichment of target analytes from complex biological matrices. The method exhibited good linearity across compound-specific calibration ranges (R2 = 0.9912-0.9993) with limits of quantification as low as 0.1 ng/mL. Recoveries ranged from 78.2% to 110.7%, while matrix effects remained within ±25%. Both intraday and interday precisions met commonly accepted validation criteria (RSD < 20%). Excellent agreement with HPLC-MS/MS results confirmed the method's analytical reliability. Although tested on a limited number of samples, the method demonstrated robust performance in two real-case blood samples and four spiked samples, highlighting its practical potential for the rapid screening and exposure assessment of insecticides and acaricides in time-sensitive forensic casework.

Keywords:  direct analysis in real‐time tandem mass spectrometry (DART‐MS/MS); dispersive liquid–liquid microextraction (DLLME); human blood; insecticides and acaricides

DOI:  https://doi.org/10.1002/jms.70070
Environ Sci Technol. 2026 Jun 09.

ToxBase: A Multidimensional ToxCast Reference Database for High-Throughput Human Exposome Analysis.

Ryan Nguyen, Griffin Rangel, Xingzhu Liu, Reuben A Santoso, Amogh Bantwal, Dylan H Ross, Ryan P Seguin, Jennifer Liem, Yvonne S Lin, Brian Pratt, Brendan X MacLean, Michael J MacCoss, Libin Xu.

  High-resolution mass spectrometry (HRMS) is the gold-standard technique for comprehensively profiling chemical exposures in complex human matrices, making it a powerful analytical tool for advancing human exposome research. Yet the scarcity of HRMS reference data, including collision cross-section (CCS) measurements from ion mobility-mass spectrometry (IM-MS) and MS/MS fragmentation spectra, hinders confident structural annotation of chemical exposure agents across laboratories. We therefore developed ToxBase, a multidimensional (m/z, retention time, CCS, MS/MS) reference database for over 2,000 chemicals sourced from the U.S. Environmental Protection Agency's ToxCast chemical library. Built via high-throughput liquid chromatography-ion mobility-tandem mass spectrometry (LC-IM-MS/MS), the ToxBase database comprises 3,598 precursor ions spanning 2,075 unique compounds with excellent precision (98.5% of compounds display interday CCS RSDs < 1%) and strong cross-platform agreement. A high-quality MS/MS reference library of the fragmented precursors was assembled using targeted data-dependent acquisition and DDARawProcessor, a novel data extraction algorithm. When applied to LC-IM-MS/MS data obtained from human plasma, urine, and fecal samples (n = 20 per matrix), ToxBase rapidly enabled 42 high-confidence (Level 1) identifications. The ToxBase database is freely available and compatible with the open-source MS data processing platform Skyline for vendor-agnostic suspect screening workflows, providing a valuable resource for standardized, large-scale exposome analysis.

Keywords:  MS/MS; ToxCast; collision cross section; exposome; ion mobility-mass spectrometry; suspect screening

DOI:  https://doi.org/10.1021/acs.est.5c18068
Biomed Chromatogr. 2026 Jul;40(7): e70511

A Validated UPLC-MS/MS Assay for Isosakuranetin Determination in Rat Plasma and Its Application to Pharmacokinetics.

Mengzhi Xu, Xiaoyu Huang, Shuman Xue, Chengrui Hu, Congcong Wen, Xianqin Wang.

  Isosakuranetin is a natural flavonoid containing a 4'-O-methyl group on the molecular structure and has a broad range of pharmacological activities. In this study, a sensitive and robust UPLC-ESI-MS/MS method was developed and fully validated for quantitative determination of isosakuranetin in rat plasma, enabling a comprehensive evaluation of the pharmacokinetics and oral bioavailability of isosakuranetin. Isoscoparin was the internal standard (IS). The plasma samples were prepared by protein precipitation with acetonitrile. Chromatographic separation was conducted with a BEH C18 column and a gradient mobile phase consisting of acetonitrile and 0.1% formic acid aqueous solution. The detection was accomplished in negative electrospray ionization (ESI) by multiple reaction monitoring (MRM) mode. The assay had excellent linearity (r > 0.995) in a linear concentration range of 0.5-800 ng/mL. Precision (intra- day and inter-day) was less than 13%, and extraction recovery was above 89%. Accuracy was between 91% and 113%, and the matrix effects were 93%-104%. Overall, this method was rapid, specific, reproducible, and sufficiently sensitive for in vivo pharmacokinetic studies in rats. After oral administration, the absolute bioavailability of isosakuranetin was calculated to be 64.6%.

Keywords:  UPLC–MS/MS; bioavailability; isosakuranetin; pharmacokinetics; rat

DOI:  https://doi.org/10.1002/bmc.70511
Biomed Chromatogr. 2026 Jul;40(7): e70517

A Simple and Rapid HPLC-MS/MS Method for Quantification of 15,16-Dihydrotanshinone I in Plasma and the Application to Pharmacokinetic Study.

Lv Dan, Huang Haijin, Liu Qian, Wu Yeming, Peng Guoshuang, You Jian, Sun Yongbing.

  In this study, a rapid and simple HPLC-MS/MS method was developed for the quantification of 15,16-dihydrotanshinone I (DHTS) in rat plasma. DHTS was well retained and separated from the polar endogenous components on a C18 column, and a triple-quadrupole mass spectrometry equipped with an electrospray ionization (ESI) source was applied for quantification. A simple protein precipitation pretreatment method could provide high extraction recovery (from 93.6% to 98.4%) and negligible matrix. The method demonstrated excellent linearity across the concentration range of 0.1~1000.0 ng/mL for DHTS. The precision and accuracy were within acceptable limits. The lowest limit of quantification (LLOQ) was determined to be 0.1 ng/mL. This simple method was validated and successfully applied to support the pharmacokinetics study after DHTS was administered to the Sprague-Dawley rats.

Keywords:  15,16‐dihydrotanshinone I; HPLC‐MS/MS; pharmacokinetic study; protein precipitation

DOI:  https://doi.org/10.1002/bmc.70517
Biomed Chromatogr. 2026 Jul;40(7): e70519

Quantification of Bullatine A and Bullatine B in Rat Plasma Using UPLC-MS/MS and Application to Pharmacokinetics.

Hao Liu, Chen Gan, Yuxin Wu, Chenyao Xu, Congcong Wen, Xintao Dai.

  A highly specific and sensitive UPLC-MS/MS assay was established and validated for simultaneous determination of bullatine A and bullatolide B in rat plasma. Midazolam was employed as the internal standard (IS). Separation was performed on a Waters UPLC BEH C18 column using a gradient mobile phase consisting of methanol and 0.1% aqueous formic acid. Detection was carried out in the mode of multiple reaction monitoring (MRM), m/z 344.3 → 105.0 (bullatine A), m/z 438.6 → 154.2 (bullatine B), and m/z 326.2 → 291.4 (IS). Plasma proteins were effectively precipitated with acetonitrile prior to analysis. Good linear calibration curves (r2 > 0.995) were obtained in a range of 0.5-600 ng/mL for both analytes, with a limit of quantification of 0.5 ng/mL. Both intra- and inter-day precision (percent RSD) were less than 14% for bullatine A and less than 13% for bullatine B. Accuracy (percentage nominal concentration) was within the range of 91%-109% for all quality control levels. The proposed method exhibited excellent sensitivity and selectivity and was successfully applied to compare the pharmacokinetics following intravenous and oral administration in rats. The absolute oral bioavailability was determined to be 4.3% for bullatine A and 12.8% for bullatine B.

Keywords:  UPLC–MS/MS; bullatine A; bullatine B; pharmacokinetics

DOI:  https://doi.org/10.1002/bmc.70519
BMC Pharmacol Toxicol. 2026 Jun 09.

Development and application of a simple LC-MS/MS method for therapeutic drug monitoring to guide colistin dosing in critically Ill patients.

Yueyuan Wang, Yani Gu, Kai Fan, Chen Feng, XinYun Zhang, Aiming Shi, Yunli Yu.

   OBJECTIVES: This study aims to develop a simple, rapid, and cost-effective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determining the concentration of colistin in human serum, including its two active components, colistin A and colistin B, to support routine therapeutic drug monitoring (TDM).
METHODS: Protein precipitation was performed using pure acetonitrile, with polymyxin B1 as the internal standard (IS). Chromatographic separation was achieved using a Phenomenex KINETEX XB-C18 column (2.6 μm, 3 × 50 mm) with a gradient elution system consisting of 0.1% formic acid (FA) in water and pure acetonitrile as the mobile phase. Detection was carried out using an electrospray ionization (ESI) source in positive ion mode with multiple reaction monitoring (MRM). After applying the validated method to critically ill patients for approximately one year, we used the receiver operating characteristic (ROC) curve to identify the preliminary cut-off value of colistin trough concentration for predicting acute kidney injury (AKI).
RESULTS: The total runtime for chromatographic separation and mass spectrometric detection was 5 min. Excellent linearity was achieved over the concentration range of 0.27-8.69 µg/mL for colistin A and 0.08-2.56 µg/mL for colistin B, with R2 greater than 0.99 for both analytes. The method demonstrated acceptable matrix effects and recovery rates. In addition‌, the ROC curve analysis of colistin TDM in critically ill patients determined a preliminary cut-off value for AKI at a trough concentration of 2.22 µg/mL.
CONCLUSION: The validated method enables simultaneous and precise quantification of the two active substances, with a simple procedure and minimal analytical cost. The utility of TDM in critically ill patients is paramount for individualizing dosing regimens to optimize outcomes and safety. Specifically, the correlation between trough concentration and AKI risk highlights the importance for clinicians to monitor renal function during colistin treatment to prevent drug-induced AKI.
CLINICAL TRIAL NUMBER: Not applicable.

Keywords:  Acute kidney injury; Colistin; Colistin methanesulfonate; Liquid chromatography-tandem mass spectrometry; Therapeutic drug monitoring

DOI:  https://doi.org/10.1186/s40360-026-01162-8
BMC Plant Biol. 2026 Jun 11.

Untargeted metabolomics suggests a trade-off between phenolamides and flavonoids in the pollen of Petunia hybrida with contrasting flower colours.

Matheus Fernandes Alves, Abigail Moreno-Pedraza, Paula Carolina Pires Bueno, Khabat Vahabi, Nicole M van Dam.

   BACKGROUND: Pollen is vital for reproduction of flowering plants. Several nutritional and biological benefits for humans and pollinators are described and related to its richness and diversity of metabolites. However, the chemical composition of pollen from several horticulturally significant plant species, such as those in the genus Petunia, has not been thoroughly characterised. Here, we present the first comprehensive description of the chemical profile of two distinct P. hybrida lines: V26 (violet flowers) and W115 (white flowers) using untargeted metabolomics. Our workflow started from pollen sampling and isolation, followed by a 3-in-1 liquid phase extraction for wide-range metabolite recovery, and data acquisition by ultra-high-performance liquid chromatography coupled to high-resolution tandem mass spectrometry (UHPLC-HRMS/MS) using three chromatographic columns (C8, C18, and HILIC) with positive and negative ionisation. For data analysis, we implemented a user-friendly and reproducible data processing pipeline based on open-source computational tools.
RESULTS: The P. hybrida pollen is rich in glycosylated flavonoids, phenolamides, and lipids, which were detected mostly in non-polar phase extracts analysed by reversed-phase chromatography. Simple phenylpropanoids, fatty acids, amino acids, and terpenoids were annotated to a lesser extent. Statistical analyses integrated with molecular networking demonstrated a distinct metabolic dichotomy: phenolamide derivatives are predominantly present in the pollen of the V26 line, while flavonoids are accumulated in the pollen of W115. This finding suggests different regulation of the phenylpropanoid metabolism in pollen of P. hybrida lines with differing flower colours and sheds light on hypotheses of ecological roles of pollen secondary metabolites, for example, in plant-pollinator interactions.
CONCLUSIONS: Our findings suggest a metabolic trade-off in the phenylpropanoid pathway in the two studied P. hybrida lines. These cultivar-specific chemical signatures may have significant implications for pollen viability and interactions with pollinators. Furthermore, our analytical and computational workflow serves as a robust template for the deep metabolic profiling of other under-characterised and complex natural matrices.

Keywords:   Petunia hybrida ; Liquid chromatography - mass spectrometry; Metabolic profiling; Phenylpropanoids; Pollen analysis; Pollen metabolomics; Specialised metabolites

DOI:  https://doi.org/10.1186/s12870-026-08968-y
Front Vet Sci. 2026 ;13 1837846

Differences among canine serum, plasma and urine metabolite profiles from samples that were collected at the same time.

Robin Moore, Johanna Anturaniemi, Vidya Velagapudi, Anna Hielm-Björkman.

   Background: Biospecimen choice can substantially influence metabolite measurements, yet matched comparisons of serum, EDTA plasma, lithium-heparin plasma, and urine remain limited in canine targeted metabolomics.
Objectives: To evaluate cross-matrix comparability of targeted small polar metabolite profiles in dogs and to assess how different biospecimens capture diet- and health-associated variation.
Animals: Client-owned dogs from a previously reported feeding trial.
Methods: Targeted ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was performed on matched biospecimens from a baseline blood-matrix cohort (serum, EDTA plasma, lithium-heparin plasma) and an end-of-trial serum-urine cohort. Metabolites with >20% missing values within a matrix and samples with >20% missing metabolite values within a biofluid were excluded. Cross-matrix agreement was assessed using Pearson correlation and mean paired log10 concentration differences. PCA and PERMANOVA were used to compare global matrix effects and diet- and health-associated separation.
Results: After filtering, 88 metabolites remained for serum, 85 for EDTA plasma, and 88 for lithium-heparin plasma in the blood-matrix cohort. Globally, EDTA plasma separated clearly from both serum and lithium-heparin plasma, whereas serum and lithium-heparin plasma overlapped substantially. At the metabolite level, 10/84 (11.9%) serum-EDTA plasma, 16/88 (18.2%) serum-lithium-heparin plasma, 20/84 (23.8%) lithium-heparin plasma-EDTA plasma, and 4/75 (5.3%) serum-urine comparisons were comparable to varying degrees. Serum showed the clearest diet-associated separation at baseline (PERMANOVA pseudo-R 2 = 0.13, p = 0.013) and end-of-trial (pseudo-R 2 = 0.22, p = 0.021). Health-associated separation was weak and exploratory.
Conclusions and Clinical Importance: Biospecimen choice materially affects targeted metabolite profiling in dogs. Serum and lithium-heparin plasma were globally more similar to each other than either was to EDTA plasma, whereas urine was a distinct complementary matrix rather than a blood surrogate. Serum was the most robust matrix for detecting diet-associated variation.

Keywords:  canine; metabolomics; plasma; serum; urine

DOI:  https://doi.org/10.3389/fvets.2026.1837846
J Vis Exp. 2026 May 22.

A Standardized Metabolomics Protocol For Analyzing Exercise-Induced Metabolic Shifts In Elite Boxers By Liquid Chromatography-Mass Spectrometry.

Peng Sun, Dong Zhang, Qinyi Chen, Mengyang He, Biao Li.

Elite boxing induces rapid metabolic changes that are not fully captured by conventional physiological measurements. A standardized untargeted serum metabolomics workflow based on liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (LC-QTOF-MS/MS) was applied to samples collected before sparring, immediately after sparring, and 24 h after sparring in seven elite male boxers. The workflow included standardized sample collection, pooled quality-control monitoring, metabolite profiling, multivariate statistical analysis, and pathway interpretation. Acute sparring was associated with changes in metabolites related to glycolysis and gluconeogenesis, whereas the 24-h timepoint was associated with sulfur metabolism. Phosphatidylinositol PI(16:0/18:2(9Z,12Z)) showed strong discrimination of the immediate post-sparring state, and thiosulfate was associated with the 24-h recovery state. These findings support the use of this workflow for reproducible profiling of exercise-related metabolic changes in this cohort of seven elite male boxers. The protocol is intended for controlled small-cohort studies of acute exercise and short-term recovery and emphasizes reproducible sample handling, pooled quality-control monitoring, and interpretable downstream analysis.

DOI: https://doi.org/10.3791/70719
Biomed Chromatogr. 2026 Jul;40(7): e70515

An Optimized Sample Pretreatment Method Followed by a Validated LC-MS/MS Method for Quantifying 6-TG and 6-MMP Concentrations in Red Blood Cells for Therapeutic Drug Monitoring in Inflammatory Bowel Disease Patients Using Thiopurines.

Inge R F van Berlo-van de Laar, Willem M J Basten, Maurits E L Arbouw, Rianne A Weersink.

  A rapid and sensitive LC-MS/MS method was developed and validated for quantifying 6-TG and 6-MMP concentrations in erythrocytes. This method is applicable for routine therapeutic drug monitoring in inflammatory bowel disease patients using thiopurines. Red blood cell (RBC) count was performed after washing the blood samples. After storage at -20°C, protein precipitation followed by acidic hydrolysis was performed using 0.062 mol/L DTT and 1.36 mol/L perchloric acid with an incubation time of 60 min at 100°C. Chromatographic separation was performed on an Acquity UPLC HSS T3 column (2.1 × 100 mm, 1.8 μm) using ammonium formate 5 mmol/L in 0.1% aqueous formic acid and methanol in gradient elution at a flow rate of 0.4 mL/min. Detection was performed in multiple reaction monitoring mode using positive electrospray ionization. The method was linear over a calibration range of 25-1500 pmol/100 μL for 6-TG and 250-8000 pmol/100 μL for 6-MMP. The method demonstrated good performance in terms of intraday and interday accuracy (96.2%-110.8%) and precision (CV 0.9%-3.9%). Calibration and QC samples were stable for 3 months at -80°C. The method demonstrated excellent performance in proficiency testing.

Keywords:  LC–MS/MS; inflammatory bowel disease; therapeutic drug monitoring; thiopurines

DOI:  https://doi.org/10.1002/bmc.70515
BMC Chem. 2026 Jun 07.

Development and bioanalytical validation of a high-sensitivity LC-MS/MS assay for quantitative determination of sotagliflozin in rabbit plasma and its stability across controlled storage conditions.

Smit Jayantilal Patel, Hiralben Mehta, Basheer Ahmmad Shaik, Nadeem Khan.

  Sotagliflozin is a dual SGLT-1 and SGLT-2 inhibitor approved by the FDA in 2023 which has emerged as a novel therapeutic agent for the management of type 2 diabetes mellitus. In this study robust and sensitive LC-MS/MS method was developed and validated for quantification of sotagliflozin in rabbit plasma as rabbit is commonly used non-rodent model for preclinical research. Sample preparation involved protein precipitation for efficient analyte extraction from rabbit plasma. Chromatographic separation was performed utilizing on BDS Hypersil C18 column (100 mm x 4.6 mm, 5 μm) using mobile phase composed of methanol (85%) and 5 mM ammonium acetate in milli-Q water (15%) and rolipram as internal standard. The method employed flow rate of 0.7 mL/min with a total runtime of 4 min and an injection volume of 10 µL. Method validation was carried out in accordance with ICH M10 guidelines, covering precision, accuracy, selectivity, recovery, and stability at different storage conditions. The method was found to be linear over the concentration range of 10-1280 ng/mL with sensitivity of 10.20 ng/mL (LLOQ) in rabbit plasma. Recovery of analyte from the rabbit plasma was found to be > 92% with stability > 99% at different storage conditions (viz., room temperature, autosampler, freeze-thaw and frozen). Overall, the developed LC-MS/MS method offers a simple, precise and reproducible approach for the quantification of sotagliflozin in rabbit plasma and is well-suited for application in pharmacokinetic and other preclinical studies.

Keywords:  LC-MS/MS; Protein precipitation; Rabbit plasma; Rolipram; Sotagliflozin

DOI:  https://doi.org/10.1186/s13065-026-01839-5
Talanta. 2026 Jun 08. pii: S0039-9140(26)00739-3. [Epub ahead of print]310 130083

Isocratic zwitterionic HILIC-ESI-MS method for assay of ropinirole and quantitation of degradation impurities in extended-release tablets.

Vasiliki Brakoulia, Ariadni Geballa-Koukoula, Dimitrios Bogeas, Andreas Kakouris, Irene Panderi.

  Given the therapeutic importance of ropinirole in Parkinson's disease and its long-term use, reliable quality control of this drug is required, with particular emphasis on impurity control in the finished pharmaceutical product. A zwitterionic hydrophilic interaction liquid chromatography-electrospray ionization mass spectrometry (HILIC-ESI-MS) method was developed and validated for the determination of ropinirole and three degradation impurities in pharmaceutical tablets. Chromatographic separation was achieved on a ZIC®-HILIC column (150 × 2.1 mm, 3.5 μm particle size, 200 Å) under isocratic elution with a mobile phase of 18.8 mM aqueous ammonium formate solution at pH 6.20 and acetonitrile in an 8:92 (v/v) ratio, delivered at a flow rate of 0.25 mL min-1. Detection was performed in positive electrospray ionization mode using selected ion monitoring and the target analytes were determined within 10 min for assay and 16 min for impurity testing. The method was validated for linearity, accuracy, precision, sensitivity, robustness, and selectivity. Calibration curves showed good linearity over the concentration range of 21 to 122 ng mL-1 with correlation coefficients of at least 0.997. Intra-day precision (% CV) did not exceed 6.7 %, while total precision ranged between 2.5 and 8.8 % for all compounds. The method was successfully applied to the analysis of commercially available ropinirole extended-release tablets. To the best of our knowledge, this is the first reported HILIC-ESI-MS method for the assay of ropinirole and the quantitation of three degradation impurities in pharmaceutical tablets.

Keywords:  HILIC; Hydrophilic interaction liquid chromatography; Impurities; LC-MS; Method validation; Ropinirole

DOI:  https://doi.org/10.1016/j.talanta.2026.130083
Gigascience. 2026 Jun 10. pii: giag069. [Epub ahead of print]

MultiMS2: A curated multi-modal, multi-energy spectral library for metabolomics.

Adriano Rutz, Mario S P Correia, Nicola Zamboni.

   BACKGROUND: Spectral libraries are essential for mass spectrometry-based metabolomics, enabling accurate metabolite annotation. Collision-induced dissociation (CID) dominates existing public libraries, but is rarely sufficient for structural elucidation. Electron-activated dissociation (EAD) provides complementary, radical-driven fragmentation, but remains sparsely represented. The lack of datasets spanning multiple dissociation mechanisms, energies, and ionization modes limits both analytical workflows and the development of robust machine learning models.
FINDINGS: We present MultiMS2, a curated metabolomics spectral library comprising 43,728 MS/MS spectra from 2,899 unique compounds. Spectra were acquired using both CID and EAD at three energies each, in positive and negative ionization modes. The dataset substantially expands publicly available EAD coverage while preserving matched acquisition conditions across energies and dissociation types.
CONCLUSIONS: By systematically combining CID and EAD across multiple energies and polarities, MultiMS2 provides a unique resource for metabolite annotation, benchmarking, and machine learning. The library supports energy-aware and dissociation-aware analysis, enabling methodological innovation and improved generalization in computational metabolomics.

Keywords:  Collision-induced dissociation; Electron-activated dissociation; Metabolomics; Spectral library

DOI:  https://doi.org/10.1093/gigascience/giag069
Molecules. 2026 May 25. pii: 1822. [Epub ahead of print]31(11):

Untargeted and Targeted Cerebrospinal Fluid Neurometabolomics via Chromatography-Mass Spectrometry-Based Methods.

Alisa K Pautova.

  Neuroscience is a rapidly advancing field; however, a comprehensive understanding of brain function at the molecular, cellular, and systems levels remains incomplete. Neurological and psychiatric disorders represent a major global health burden, highlighting the need for improved diagnostic and therapeutic strategies. Cerebrospinal fluid (CSF) is one of the most informative biofluids for investigating central nervous system (CNS) pathology due to its close biochemical relationship with brain tissue. Recent advances in neurometabolomics, defined as the comprehensive analysis of small-molecule metabolites in CSF, have been driven by the development of highly sensitive and informative mass spectrometry-based techniques. These approaches enable the identification of disease-associated metabolic signatures. This review summarizes current chromatography-mass spectrometry-based methods used in both untargeted and targeted CSF metabolomics, with particular emphasis on their analytical performance, reproducibility, and limitations. Special attention is given to method standardization and validation, as well as to the identification of reliable metabolic biomarkers for the diagnosis and monitoring of neurological disorders, including neurodegenerative, psychiatric, oncological, and neuroinflammatory diseases.

Keywords:  biomarkers; central nervous system; diagnosis; gas chromatography–mass spectrometry; liquid chromatography–mass spectrometry; metabolites; standardization; targeted analysis; untargeted analysis; validation

DOI:  https://doi.org/10.3390/molecules31111822
Bioinform Adv. 2026 ;6(1): vbag138

eMZed 3: flexible and interactive development of scalable LC-MS/MS data analysis workflows in python.

Uwe Schmitt, Jethro Hemmann, Nicola Zamboni, Julia A Vorholt, Patrick Kiefer.

Summary: Liquid chromatography-mass spectrometry (LC-MS/MS) data analysis requires adaptable software solutions to meet diverse analytical needs. We present eMZed 3, a modern Python framework for flexible and interactive analysis of LC-MS/MS data. eMZed 3 enables users to develop scalable workflows tailored to their specific requirements while leveraging Python's extensive ecosystem of libraries. Building on its predecessor, eMZed 3 is now Python 3-based and includes substantial enhancements, including support for chromatogram-based LC-MS data, a new SQLite-based backend supporting optional out-of-memory processing, and rich interactive visualization tools. Compared to the previous version, eMZed 3 is now split into three packages: emzed (core functionalities), emzed-gui (interactive data visualization), and emzed-spyder (an integrated development environment). This modular architecture allows straightforward integration of the emzed core library into headless Python environments, including computational notebooks (such as Jupyter) or high-performance computing clusters. eMZed 3 incorporates well-established libraries such as OpenMS, and is suited for both targeted and untargeted metabolomics. Overall, eMZed 3 supports the efficient development of scalable and reproducible LC-MS data analysis and is accessible to both novice and advanced programmers.
Availability and implementation: eMZed 3 and its documentation are freely available at https://emzed.ethz.ch, the source code is hosted at https://gitlab.com/groups/emzed3.An online-executable example workflow is available on Binder at: https://mybinder.org/v2/gl/emzed3%2Femzed-example-workflow/HEAD?_labpath=example.ipynb.

DOI: https://doi.org/10.1093/bioadv/vbag138
Molecules. 2026 May 22. pii: 1780. [Epub ahead of print]31(11):

Development and Optimisation of an HPLC-MS/MS Workflow for Profiling Selenium and Sulphur Amino Acids in Soybean Leaves and Investigation of Se-S Metabolic Interactions.

Xiaohui Cai, Jun Men, Qingwu Yang, Yili Hu, Zhixian Qiao.

  A derivatisation-free HPLC-MS/MS method was developed and validated for the simultaneous quantification of selenium- and sulphur-containing amino acids in soybean leaves, and applied to a 3 × 3 factorial hydroponic experiment probing selenium-sulphur metabolic interactions. The method resolves five biologically informative analytes (Cys2, SeCys2, MeSeCys, Met, SeMet) within 1.5 min through multiple reaction monitoring (MRM). Ultrasound-assisted extraction (UAE) of the free fraction was jointly optimised for both analyte classes by the response-surface methodology; enzymatic hydrolysis of the extraction residue recovered the protein-bound fraction on the same platform. Limits of detection ranged from 0.036 to 0.556 µg L-1, intra-day relative standard deviations were below 5%, and spike recoveries fell between 92.3 and 117.4%. Free SeAA and SAA pools were negatively correlated across the nine treatments (R2 = 0.83), consistent with competitive Se-S assimilation, whereas bound pools were positively correlated (R2 = 0.89), reflecting proportional protein-level incorporation. A regime of 1-5 mM of sulphate with 20 µM of selenite yielded the highest bound organo-Se with near-normal growth, providing leaf-level evidence that may inform future seed-focused studies aimed at Se-enriched soy-protein ingredient development.

Keywords:  HPLC-MS/MS; multiple reaction monitoring; selenium biofortification; selenium–sulfur interaction; seleno-amino acids; soybean; ultrasound-assisted extraction

DOI:  https://doi.org/10.3390/molecules31111780
J Anal Toxicol. 2026 Jun 09. pii: bkag041. [Epub ahead of print]

Analysis of suzetrigine, a novel non-opioid pain medication, in whole blood and urine using liquid chromatography-tandem mass spectrometry.

Isabelle R Parry, Britni N Skillman.

  Suzetrigine (JOURNAVX®) is a novel non-opioid pain medication that was approved in January 2025. Given the well-documented abuse potential of opioids, suzetrigine may become more widely prescribed as an alternative for acute pain management. However, it could still appear in forensic casework as little is understood about its role in polydrug toxicity, comorbidity with pre-existing health conditions, or abuse potential within larger populations. As such, this research aimed to develop the first forensically focused method to detect suzetrigine in blood and urine. Due to its similar physicochemical properties, suzetrigine was seamlessly integrated into a previously validated liquid-liquid extraction method developed for novel dual orexin receptor antagonists (DORAs). This report focuses on the subsequent method development and validation for suzetrigine detection using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method was validated in accordance with ANSI/ASB 036 for the quantification of suzetrigine in blood and its qualitative identification in urine. A quadratic calibration model with 1/x weighing was utilized (1.0-1000 ng/mL) with quality controls (QCs) at 1.5, 80, 400, and 800 ng/mL. The limit of detection in blood and urine was 0.25 ng/mL, while the limit of quantitation in blood was 1.0 ng/mL. Post-extraction addition at 5 ng/mL and 500 ng/mL yielded matrix effects less than ± 25%, but increased variability at the low concentration in blood was deemed to have no impact on LOD. No carryover or interferences were observed from the internal standard, matrices, or common drugs. Dilution integrity (5X) was acceptable in blood, and processed samples were stable up to 72 hours in the autosampler. In this report we describe a simple extraction for suzetrigine in blood and urine followed by LC-MS/MS analysis. This analytical workflow will be valuable as the use of suzetrigine becomes more prevalent in casework samples.

Keywords:  Suzetrigine; blood; liquid chromatography–tandem mass spectrometry; novel analgesic; urine

DOI:  https://doi.org/10.1093/jat/bkag041
J Pharmacol Toxicol Methods. 2026 Jun 12. pii: S1056-8719(26)00025-0. [Epub ahead of print] 108432

Rapid and sensitive quantification of pemetrexed in human plasma by LC-MS/MS using a stable isotope-Labeled internal standard for therapeutic drug monitoring.

Haoran Yang, Huimin Yu, Tang Tang, Huijie Yue, Xiaoyi Chen, Jieyu Zhang, Yuzhu Cao, Qing Zhou.

   OBJECTIVE: To develop and validate a reliable LC-MS/MS method for quantifying pemetrexed in human plasma to investigate exposure-toxicity relationships.
METHODS: Separation utilized an Agilent ZORBAX Eclipse Plus C18 column with a gradient of acidified water and acetonitrile over 5 min. Detection was by triple quadrupole MS with positive electrospray ionization, monitoring qualifier MRM transitions m/z 428.20 → 163 (pemetrexed) and 433.20 → 163 (internal standard, pemetrexed-13C5), and quantifier transitions m/z 428.20 → 280.90 and 433.20 → 280.90 . The method was applied to therapeutic drug monitoring in a renal-impaired patient.
RESULTS: The method was linear from 10 to 1000 ng/mL (R2 = 0.9992). Accuracy ranged from 103.67% to 108.83%, with precision (RSD) <15%. The extraction recovery ranged from 94.35% to 99.19%, while matrix effects were between 102.84% and 110.22%. Pemetrexed exhibited satisfactory stability under all tested conditions, meeting bioanalytical method validation requirements. Clinical application revealed delayed elimination of pemetrexed in the patient, suggesting a threshold-based relationship between exposure and toxicity. Notably, plasma concentrations remained above the proposed toxicity threshold (0.11 mg/L) for 11 days post-chemotherapy, correlating with the development of grade IV bone marrow suppression.
CONCLUSION: A rapid, sensitive, and specific LC-MS/MS method for determining pemetrexed in human plasma was successfully developed and validated. This method is suitable for therapeutic drug monitoring (TDM). The clinical application suggests that pemetrexed-induced toxicity is likely driven by exposure exceeding a critical threshold. For patients with renal dysfunction or those on medications affecting its clearance, TDM using this method could be a valuable tool for individualized dose adjustment, thereby improving treatment safety and efficacy.

Keywords:  Drug toxicity; LC-MS/MS; Pemetrexed; Personalized medication; Therapeutic drug monitoring (TDM)

DOI:  https://doi.org/10.1016/j.vascn.2026.108432
J Mass Spectrom. 2026 Jul;61(7): e70072

A Step-by-Step Protocol From METASPACE to Biological Interpretation.

Abigail Moreno-Pedraza, Brittney Gorman, Marija Velickovic, Max Bentelspacher, Jaime Barros, Dusan Velickovic, Christopher R Anderton.

Mass spectrometry imaging (MSI) represents an exceptional tool for exploring complex biological systems spatially at the molecular level. However, its multidimensional nature and large data outputs make it challenging to extract meaningful biological insights. Advancements such as the METASPACE platform allow researchers to efficiently process, annotate, and interpret MSI datasets by leveraging machine learning and a cloud-based infrastructure. In this tutorial, we present a detailed and user-friendly R-pipeline designed to help METASPACE users navigate untargeted metabolomic annotations and translate them into practical biological insights, particularly in complex systems. This approach has broad potential applications, including diagnostics, drug discovery, environmental, and ecological research. We envision this pipeline will be particularly useful for newcomers to MSI and encourage experienced users to customize and extend it to meet more advanced analytical needs.

DOI: https://doi.org/10.1002/jms.70072
ArXiv. 2026 Jun 02. pii: arXiv:2606.05225v1. [Epub ahead of print]

The Language of Elution: Autoregressive Prediction of the Next Feature in Untargeted LC-HRMS Lipidomics.

Dayanjan S Wijesinghe.

Untargeted liquid chromatography-high-resolution mass spectrometry (LC-HRMS) detects thousands of molecular features per sample, yet only 2-20% receive confident structural annotations. A root cause of this "dark metabolome" is that tandem MS/MS acquisition is reactive: instruments select precursors only after ions appear, blind to what elutes next. We reframe chromatographic elution as an autoregressive sequence prediction task. Because reversed-phase elution order is governed by hydrophobicity, successive features form a physically constrained sequence, like tokens in language. We discretize the mass-to-charge (m/z) axis into 110 bins and train long short-term memory (LSTM) and Transformer models to predict the next eluting m/z bin from five annotation-free per-token features: m/z bin, mass defect, retention-time gap, polarity, and intensity rank. Trained on 15,242 features from four clinical lipidomics cohorts (342 plasma samples; SCIEX TripleTOF 6600+, Waters CSH C18), the LSTM reaches 98.4% top-1 accuracy (99.99% top-5; mean absolute error 3.6 Da) and the Transformer 98.0%. Ablation shows autoregressive context accounts for 55.5 percentage points while no single feature contributes more than 0.2 pp: the sequential pattern, not molecular properties, drives prediction. Models transfer across instruments sharing the method (r=0.999 on an independent Agilent 6530 dataset) but fail under a different column chemistry (5.1% top-1) or polarity mode (2.6%), confirming method- and mode-specificity. Fine-tuning on as few as two to five quality-control injections recovers held-out accuracy from 2.6% to nearly 50%, so cross-condition deployment needs minimal calibration. These results establish that elution sequences are highly predictable and lay the groundwork for predictive MS/MS acquisition to improve annotation coverage in untargeted metabolomics.
Nat Protoc. 2026 Jun 10.

Robust analytical methods for bis(monoacylglycero)phosphate profiling in health and disease.

Wentao Dong, Kwamina Nyame, Eshaan S Rawat, Uche N Medoh, Jian Xiong, Caio C Bonin, Hisham N Alsohybe, Hunter Y Liu, Sara Gomes, Tammy Shalit, Marianna Arnold, Frank Hsieh, Esther Sammler, Monther Abu-Remaileh.

Bis(monoacylglycero)phosphates (BMPs), a distinct class of anionic phospholipids predominantly found in late endosomes and lysosomes, plays a pivotal role in supporting lysosomal functions and maintaining metabolic homeostasis. Dysregulation of BMPs is associated with an array of disorders, notably neurodegenerative diseases. However, the identification and quantitation of BMP remains difficult because of its structural similarity to its isomer, phosphatidylglycerol (PG), thus necessitating robust analytical methods for accurate and reliable BMP profiling. In this study, we present comprehensive liquid chromatography (LC)-tandem mass spectrometry (MS2) methodologies for the precise and systematic analysis of BMP species in biological samples. We detail LC/MS methods for both an untargeted Orbitrap mass spectrometer and a targeted triple quadrupole mass spectrometer. We use differences in hydrophobicity and structure to annotate BMPs and PGs on the basis of retention time and positive-mode MS2 fragmentation patterns, respectively. Because genetic ablation of the BMP synthase CLN5 leads to specific depletion of BMPs but not PGs, lipid extracts from CLN5 knockout and wild-type cells can be compared to confidently annotate BMPs when MS2 data are incomplete. Lipid extraction and preparation of samples for LC/MS takes ~4 h, unattended LC/MS instrument time depends on the number of samples and computer-based data analysis takes ~1 d. Altogether, this approach constitutes a robust method for BMP profiling and annotation, furthering research into health and disease.

DOI: https://doi.org/10.1038/s41596-026-01379-1
J Sep Sci. 2026 Jun;49(6): e70465

A Robust and Universal LC-MS/MS Method for Determination of N-Nitrosodimethylamine in Pharmaceuticals Using a C30 Column.

Byungchan An, Unyong Kim, Sumin Seo, Jiyu Kim, Chohee Jeong, Woojin Jeong, Eunjin Ko, Juhyeon Kim, Hyun-Deok Cho, Sang Beom Han.

  Since the 2018 valsartan recall, the genotoxic impurity N-nitrosodimethylamine (NDMA) has been frequently detected in various pharmaceuticals. Matrix variability often complicates routine testing, requiring customized analyses. We developed a universal LC-MS/MS method enabling consistent NDMA detection across diverse pharmaceuticals. Separation utilized a C30 column (150 mm × 4.6 mm I.D., 5 µm), offering superior retention and shape selectivity for polar nitrosamines compared to conventional reversed phases. Unlike C18 or pentafluorophenyl phases, which often exhibit limited retention for NDMA, the C30 phase provides exceptional shape selectivity and enhanced hydrophobic interactions. This structural advantage, supplemented by its resistance to phase dewetting under highly aqueous conditions further ensures robust resolution between NDMA and complex drug matrices. The mobile phase consisted of 0.1% v/v formic acid in water and methanol under gradient elution at 1.0 mL/min. Detection used atmospheric pressure chemical ionization in positive ion mode. The method demonstrated a linear range of 2.0-100.0 ng/mL (r2 > 0.999), with a limit of detection of 1.0 ng/mL and a limit of quantification of 2.0 ng/mL. Validation per International Council for Harmonisation (ICH) guidelines confirmed accuracy (87.7%-115.5%) and precision (coefficient of variation, CV ≤ 10.7%). Application to 30 diverse pharmaceutical products, including sartans and ranitidine, showed robust resolution (> 2.0) between the analyte and active pharmaceutical ingredients (APIs). Notably, NDMA was quantified in historical batches of ranitidine (164.83 ± 5.68 ng/mL), nizatidine (10.25 ± 0.52 ng/mL), and amitriptyline (2.28 ± 0.19 ng/mL). While the histamine type 2 receptor antagonists significantly exceeded the acceptable daily intake limit, the remaining 27 products showed no detectable NDMA. These findings highlight the method's effectiveness for real-world surveillance and the critical risk of post-manufacturing NDMA generation during prolonged storage. This universal C30-based method provides a practical, reliable tool for routine screening, facilitating regulatory compliance and improved patient safety without drugspecific method development.

Keywords:  C30 (triacontyl) stationary phase; LC–MS/MS; N‐nitrosodimethylamine; genotoxic impurity; universal method

DOI:  https://doi.org/10.1002/jssc.70465
Crit Rev Anal Chem. 2026 Jun 11. 1-23

From Sampling to Screening: A Review of Targeted and Non-Targeted PFAS Analysis in Environmental Samples.

Magdalena Herok, Hanna Barchanska, Monika Partyka.

  Per- and polyfluoroalkyl substances (PFAS) constitute a large class of highly persistent synthetic chemicals widely distributed in environmental and biological matrices. The growing recognition of their environmental persistence, mobility, and potential adverse health effects has intensified the need for comprehensive and reliable analytical strategies. This review critically examines current approaches to PFAS determination, with emphasis on advanced analytical methodologies. Targeted liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) remains the gold standard for regulatory monitoring, but its applicability is restricted to predefined lists of known compounds. In response to the increasing structural diversity of PFAS, non-targeted and suspect screening workflows based on high-resolution mass spectrometry (HRMS) are gaining prominence, enabling identification of previously unrecognized compounds and transformation products. Special attention is devoted to screening strategies, data processing challenges, and methodological limitations. In addition, electroanalytical and sum parameter methods, including total fluorine (TOF), extractable organofluorine (EOF), and adsorbable organofluorine (AOF), are discussed as complementary tools. The review highlights the importance of harmonized sampling protocols, quality assurance, and method validation. Integrating targeted quantification, non-targeted approaches, and fluorine mass balance concepts enables comprehensive PFAS monitoring.

Keywords:  LC-MS/ms; PFAS analysis; environmental contamination; human health risk

DOI:  https://doi.org/10.1080/10408347.2026.2685273
Anal Chem. 2026 Jun 11.

Robust Metabolomics Data Normalization across Scales and Experimental Designs.

Matthijs Vynck, Pablo Vangeenderhuysen, Ellen De Paepe, Tim Nawrot, Vera Plekhova, Lynn Vanhaecke.

Metabolomics studies employing liquid chromatography-mass spectrometry are affected by signal drift and batch effects, introducing technical variance that impedes biological knowledge discovery. Quality control (QC) sample-based normalization strategies are widely implemented but remain vulnerable to outliers, thereby reducing normalization performance. We introduce rLOESS, rGAM, and tGAM, three robust normalization methods that improve resistance to outliers by downweighting or accommodating them. Leveraging additive models, the rGAM and tGAM methods allow flexible nonlinear modeling, differential sample weighting, and data-driven QC representativeness evaluation. Implementations of these methods are gathered in the Metanorm R package, integrating robust normalization with visualization for performance verification while supporting efficient parallel processing. In in silico and/or experimental data sets, the robust methods, relative to several popular existing strategies, improved replicate concordance and reduced drift and batch effects. The robust methods, with improved recovery of the underlying signal demonstrated in simulation, produced distinct differential abundance results, highlighting the impact of normalization on downstream statistical inference. Overall, tGAM-based normalization suggested the best performance across scenarios and is proposed as the default choice. Metanorm is versatile, supporting normalization in metabolomics studies across scales and experimental setups. Metanorm is freely available at https://github.com/UGent-LIMET/Metanorm.

DOI: https://doi.org/10.1021/acs.analchem.5c06841
Molecules. 2026 May 29. pii: 1868. [Epub ahead of print]31(11):

Chemical Profiling of Aboveground and Underground Parts of Pterocephalus hookeri by Integrated FBMN, Untargeted LC-MS Metabolomics, and PAD-DESI-MSI.

Jiaxing Luo, Lanlan Fang, Muze Yu, Di Yang, Jing Zhang, Jia Yu, Ce Tang, Tingting Kuang.

  Pterocephalus hookeri (C.B.Clarke) Höeck is a classic traditional Tibetan medicinal herb with multiple pharmacological activities. The inconsistent usage of its medicinal parts (whole herb, aboveground part (AP), and underground part (UP)) in commercial circulation severely restricts its clinical safety and quality stability. Currently, most existing chemical investigations focus on the whole herb, whereas the intraspecific chemical discrepancies between AP and UP remain poorly clarified. Herein, an integrated analytical strategy combining ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS)-based untargeted metabolomics, feature-based molecular networking (FBMN), and paper-based analytical device desorption electrospray ionization mass spectrometry imaging (PAD-DESI-MSI) was established to characterize differential metabolites and their spatial distribution in P. hookeri. A total of 101 compounds were annotated, and 12 vital differential metabolites were further screened with variable importance in projection (VIP) values > 1. The visualized distribution differences of these biomarkers were validated via heatmap and PAD-DESI-MSI analysis. Obvious differences in chemical accumulation characteristics were confirmed between AP and UP, which can guide reasonable clinical medication and rational dosage regulation referring to metabolite abundance. Moreover, optimized data filtering thresholds effectively eliminated metabolomic false positives, and FBMN exhibited excellent capacity for differential biomarker screening. This study provides a solid chemical basis for the quality evaluation and rational medicinal application of P. hookeri.

Keywords:  DESI-MSI; Pterocephalus hookeri; UPLC-Q-TOF/MS; different medicinal parts; differential markers; feature-based molecular networking; untargeted metabolomics

DOI:  https://doi.org/10.3390/molecules31111868
ACS Omega. 2026 Jun 02. 11(21): 30561-30569

Comprehensive Metabolomic Analysis of Saliva Using SWATH-DIA Reveals Systemic Metabolic Adaptations to Exercise.

Maroof Athar Hashmi, Diksha Gogia, Nirpendra Singh, Arvind Ramanathan.

Saliva is an accessible, noninvasive biofluid for real-time monitoring of physiological and metabolic changes. However, its potential to capture physical-exciton-induced biochemical responses has been limited by the metabolite identification depth and reproducibility of conventional metabolomics tools. In this study, we established a Sequential Window Acquisition of All Theoretical Fragment-Ion Spectra (SWATH-DIA)-based untargeted LC-MS metabolomics workflow for comprehensive profiling and relative quantitation of the salivary metabolome before and after physical exercise. Saliva samples were collected from 27 recreational runners before and immediately after a standardized 5 km run to investigate acute metabolic fluctuations in participants. The Zeno SWATH-DIA method enabled the simultaneous acquisition of precursor and fragment ion spectra across the full m/z range (50-800 Da) in positive and negative mode of electrospray ionization (ESI), resulting in detection and validation metabolites spanning lipids, amino acids, organic acids, carbohydrates, and short-chain carnitines. Compared with traditional data-dependent acquisition (DDA) approaches, Zeno SWATH-DIA provided enhanced metabolite coverage, improved reproducibility, and reduced precursor selection bias (a statement of quantitation of how much more). Multivariate analyses (PCA, OPLS-DA) revealed clear separation between pre- and postexercise samples, highlighting metabolic shifts involving carbohydrate metabolism (lactate, pyruvate), fatty acid oxidation (acylcarnitines, glycerol), amino acid turnover (BCAAs, arginine, ornithine), and nitrogen metabolism (urea, spermidine). Collectively, these findings establish Zeno SWATH-DIA saliva metabolomics as a robust, high-coverage analytical approach for noninvasive assessment of acute metabolic responses to the exercise-induced physiological changes. The workflow provides a methodological foundation for future integrative studies linking saliva-based metabolomics with performance, fatigue, and metabolic health monitoring.

DOI: https://doi.org/10.1021/acsomega.5c11847
Foods. 2026 Jun 03. pii: 2001. [Epub ahead of print]15(11):

Suspected and Non-Targeted Screening of Non-Edible Substances in Food by UPLC-Q-TOF-MS.

Ting Wang, Fuhong Chen, Lirong Pan, Wenxuan Yuan, Jie Pang, Xianliang Li, Cunxian Xi, Dunming Xu.

  A screening method based on dispersive solid-phase extraction (DSPE) coupled with ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was established for the analysis of non-edible substances in food. This method is applicable to a wide range of non-edible substances, including but not limited to antihypertensive, hypoglycemic, weight-loss, antimicrobial, antipyretic-analgesic, sedative-hypnotic, and antifatigue agents. Through systematic optimization of sample pretreatment and UPLC-Q-TOF-MS conditions, ultrasonic extraction with methanol followed by cleanup using 25 mg Primary Secondary Amine (PSA) and 50 mg C18 was identified as the optimal procedure. The methodological validation demonstrated that all 38 quality control compounds exhibited excellent linear correlation coefficients (R2 > 0.99) across a concentration range of 0.005~5.0 mg/kg. At three spiking levels, the mean recoveries and relative standard deviations (RSDs) in four matrices ranged from 67.79% to 110.93% and from 0.23% to 9.37%, respectively. The screening detection limits (SDLs) and limits of quantification (LOQs) were within the range of 0.003~0.5 mg/kg. A screening database comprising 390 substances was constructed. In addition, an identification strategy for the unknown structural analogues was established by summarizing the mass spectrometric fragmentation patterns of the phosphodiesterase-5 (PDE-5) inhibitor analogues. Applied to 110 batches of samples, the method screened 12 known non-edible substances and identified a new PDE-5 inhibitor analogue, phenyl 3-desethyl 3-propyl carbodenafil. The workflow integrates suspected screening using a comprehensive database with a non-targeted identification strategy for unknown analogues. Overall, this strategy is efficient, sensitive and accurate, providing a robust analytical platform for high-throughput screening and discovery of illegally added unknown substances in food.

Keywords:  PDE-5 inhibitors; dispersive solid-phase extraction; high-resolution mass spectrometry; non-edible substances; suspected screening; unknown structural analogues

DOI:  https://doi.org/10.3390/foods15112001
J AOAC Int. 2026 Jun 08. pii: qsag049. [Epub ahead of print]

Analysis of Taurine in Infant Formula and Adult Nutritionals by HILIC-MS/MS: Collaborative Study, AOAC Official Method 2022.03:2026, Final Action.

Brendon D Gill, Jackie E Wood, Geert A Ten Kate.

BACKGROUND: Taurine is recognized as an essential growth factor and as being critical in the maintenance of functional tissue regulation. The fortification of taurine to infant formulas is necessary to provide sufficient nutrient to maintain serum levels equivalent to those of their counterparts fed on their mother's milk.
OBJECTIVE: To evaluate method reproducibility of AOAC 2022.03 Official First Action method for compliance with the performance requirements described in AOAC Standard Method Performance Requirements (SMPR®) 2014.013.
EXPERIMENTAL: Following protein precipitation with Carrez solutions, taurine is extracted and analyzed by hydrophilic interaction liquid chromatography-tandem mass spectrometry using multiple reaction monitoring. Stable isotope labelled taurine internal standard is used for quantification to correct for losses in extraction and variations in ionization in the ion source.
RESULTS: Thirteen laboratories participated in the analysis of blind-duplicate samples of seven nutritional products. After outliers were removed, precision as reproducibility was found to be within limits set in SMPR 2014.013 (≤ 8%) for all seven test samples and all had acceptable HorRatR values ranging from 0.4 to 0.7.
CONCLUSIONS: The method described is suitable for the quantification of taurine in infant formulas and adult nutritionals. The AOAC Expert Review Panel for the Stakeholder Program for Infant Formula and Adult Nutritionals evaluated the method and accompanying validation data from this multi-laboratory testing study in June 2025 and recommended Official Method 2022.03 for adoption as a Final Action Official Method.
HIGHLIGHTS: A multi-laboratory testing study of a HILIC-MS for the determination of taurine is described.

DOI: https://doi.org/10.1093/jaoacint/qsag049
Plants (Basel). 2026 May 28. pii: 1651. [Epub ahead of print]15(11):

Medicinal Amazonian Oleoresins: An Eco-Friendly Chemical Fingerprinting Method.

Rayssa Ribeiro, Gabriel Reis Alves Carneiro, Henrique Marcelo Gualberto Pereira, Monica Costa Padilha, Valdir F Veiga-Junior.

  Oleoresins are complex natural lipophilic matrices traditionally analyzed using chromatographic techniques that require extensive sample preparation, derivatization, and authentic standards. Amazonian oleoresins from Copaifera and Eperua species (Fabaceae) represent valuable bioresources with recognized pharmacological potential, largely attributed to diterpenoids such as copalic and hardwickiic acids, as well as bioactive sesquiterpenes, including the cannabinoid β-caryophyllene. In this study, we present a proof-of-concept application of Direct Analysis in Real Time coupled with High-Resolution Mass Spectrometry (DART-HRMS) as a rapid, direct, and environmentally friendly approach for chemical fingerprinting and semi-targeted screening of the two most important amazonian oleoresins from these two genera: Eperua oleifera and Copaifera multijuga. Analyses were performed using a Q Exactive Orbitrap coupled to a DART ion source under optimized conditions. Hardwickiic acid was used as a model compound for method optimization, with optimal performance achieved at 200 °C and 100 V, yielding stable signal intensities (CV < 10%) and high mass accuracy (<1 ppm). The method enabled reproducible detection of diterpenic acids in both oleoresins, allowing differentiation of their chemical profiles and assessment of short-term stability under ambient conditions. In addition to diterpenes, free fatty acids were also detected, expanding the compositional characterization of these matrices. Compound annotation was performed based on accurate mass measurements and literature comparison, corresponding to Level 5 confidence according to established metabolomics criteria. Although the absence of chromatographic separation limits isomer discrimination and absolute quantification, DART-HRMS provides a rapid and solvent-free strategy for chemical fingerprinting and preliminary characterization of oleoresins. This approach aligns with Green Chemistry principles and shows strong potential as a screening and triage tool for quality control, chemotaxonomic studies, and sustainable valorization of Amazonian natural products.

Keywords:  Amazonian bioeconomy; Copaifera multijuga Hayne; DART-MS; Eperua oleifera Ducke; Green Chemistry; oleoresins

DOI:  https://doi.org/10.3390/plants15111651