bims-metlip 2026-09-20 papers

bims-metlip

Biomed News

on Methods and protocols in metabolomics and lipidomics

Issue of 2026–09–20
twenty-two papers selected by
Sofia Costa, Matterworks

Determination of Hecogenin in Mouse Blood by UPLC-MS/MS and Applied to a Pharmacokinetic Study.
Combined Lipidomic and Metabolomic Analyses on Cardiac Organoids.
Implementation of Nano Flow Chromatography Coupled to Mass Spectrometry as a Reliable and Sensitive Discovery Lipidomics Platform.
[Enzyme Digestion LC-MS/MS Detection of Etomidate, Ketamine, Methamphe‑ tamine and Codeine in Hair].
[Determination of glufosinate and its metabolite residues in tea by ultra-high performance liquid chromatography-tandem mass spectrometry coupled with precolumn derivatization].
Column switching liquid chromatography dual mass spectrometry system for simultaneous untargeted metabolomics and targeted exposomics.
A library of experimental collision cross sections for food, beverage and plant metabolites generated by reversed-phase liquid chromatography coupled to travelling-wave ion mobility and high-resolution mass spectrometry.
[Determination of 33 non-steroidal anti-inflammatory drug residues in horse urine by QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry].
Biomonitoring: a demonstration of the importance of direct analytical methods for the assessment of chemical exposures.
[Simultaneous determination of three tryptamines in foods by ultra performance liquid chromatography-tandem mass spectrometry coupled with hydrophilic column separation].
Analysis of porphyrins from serum and the benefit of inert biphenyl columns for liquid chromatography separation.
[Determination of 15 fentanyl analogs and amphetamine-type stimulants in hair by liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry].
N-Alkylpyridinium sulfonates as versatile scout compounds for multi-mode highly targeted metabolomics: Application to Gammarus fossarum.
Improving Lipid Identification and Quantification: Chromatogram Deconvolution for LC-MS/MS Workflows.
Emerging Strategies for Comprehensive Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Complex Product and Industrial Matrices.
[Application of Automatic Magnetic Solid-Phase Extraction Instrument in Toxic Substances and Illegal Drugs].
Acidified Acetonitrile Extraction and Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry for Multiresidue Determination of 136 Pesticides in Tahiti Lime (Citrus latifolia).
Novel application of reversed-phase high performance liquid chromatography-tandem mass spectrometry for enantioselective determination of cyclaniliprole enantiomers in plant-derived foods.
Liquid chromatography-high-resolution mass spectrometry-based integrated strategy combining in silico prediction and molecular networking for metabolite identification of podophyllotoxin in a fatal poisoning case.
Determination of Enantiomers of Deschloroketamine and Its Metabolites in Wistar Rat Brains.
A QuEChERS-LC-HRMS-based method for the quantification of six sulfonamides and trimethoprim residues in milk.
Protocol for targeted analysis of oxylipins in rat plasma and mouse macrophage samples by high-resolution UHPLC-MS/MS.

Biomed Chromatogr. 2026 Oct;40(10): e70618

Determination of Hecogenin in Mouse Blood by UPLC-MS/MS and Applied to a Pharmacokinetic Study.

Yujie Hu, Lei Zhu, Xueying Xiang, Tao Zou, Congcong Wen, Qiong Duan.

  Hecogenin, a steroidal sapogenin from agave plants, exhibits anti-inflammatory, anti-tumor, gastroprotective, and diuretic activities. A sensitive ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for quantifying hecogenin in mouse whole blood using swertisin as internal standard. Protein precipitation with acetonitrile enabled simple pretreatment of only 20-μL blood samples. Separation was achieved on a BEH C18 column with gradient elution, and detection was performed via multiple reaction monitoring in positive electrospray ionization mode. The assay was linear over 1-2000 ng/mL (r = 0.9988), with a lower limit of quantification of 1 ng/mL. Intra- and interday precision (RSD) were below 11% and 12%, respectively, and accuracy ranged from 93.2% to 110.4%. Matrix effects were negligible, and extraction recovery was 87.5%-91.2%. The validated method was applied to a pharmacokinetic study in male ICR mice following intravenous (5 mg/kg) and oral (10, 20 mg/kg) administration. Noncompartmental analysis revealed low oral absolute bioavailability (10.8%-12.4%).

Keywords:  UPLC‐MS/MS; bioavailability; hecogenin; method validation; mouse blood; pharmacokinetics; protein precipitation; steroidal sapogenin

DOI:  https://doi.org/10.1002/bmc.70618
Methods Mol Biol. 2027 ;3074 239-263

Combined Lipidomic and Metabolomic Analyses on Cardiac Organoids.

Lorenzo Fontanelli, Carolina Ferri, Adrian Florentin Suman, Elisa Ceccherini, Giovanni Signore, Fabio Anastasio Recchia, Silvia Rocchiccioli.

  Cardiac organoids are increasingly used to model human cardiac development and disease, but their small size often limits molecular characterization, especially if different approaches and protocols are necessary to extract and quantify metabolites and lipids. Here, we present a multistep workflow for combined targeted free amino-acid (FAA) based metabolomic and lipidomic profiling from a single pooled cardiac organoid sample. The protocol covers organoid harvesting, detergent-assisted lysis, and a modified Folch extraction that generates an organic phase for lipid analysis and an aqueous phase for FAA metabolite analysis. Lipids are quantified by Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (LC-ESI-MS/MS) in Multiple Reaction Monitoring (MRM) mode using class-matched external standards and an internal standard to support calibration and reduce technical variability. Free amino acids and derivatives are analyzed from the same sample after filtration, drying, and AccQ-Tag derivatization, with norvaline as an internal standard. Together, this approach maximizes information yield from limited material and enables integrated analysis of metabolic and lipid pathways within the same biological specimen, facilitating organoid-based studies of cardiac maturation, disease modeling, and pharmacological responses.

Keywords:  Cardiac organoids; LC–MS/MS (MRM); Modified Folch extraction; Targeted lipidomics; Targeted metabolomics

DOI:  https://doi.org/10.1007/978-1-0716-5539-9_14
Rapid Commun Mass Spectrom. 2026 Dec 15. 40(23): e70175

Implementation of Nano Flow Chromatography Coupled to Mass Spectrometry as a Reliable and Sensitive Discovery Lipidomics Platform.

Ciara J Sallowicz, Thiago Mattos, Rahul R Deshpande, Bashar Amer, Susan S Bird.

RATIONALE: Untargeted lipidomics is commonly performed at analytical flow rates, which consume more solvent and may require higher on-column sample loads when sensitivity is limited by analyte abundance. Nano flow separations use lower flow rates and sample loads, reducing solvent consumption and facilitating improved electrospray ionization. We present here practical considerations for implementing a routine nano flow lipidomics workflow.
METHODS: Bovine liver total lipid extract was spiked with SPLASH Lipidomix internal standards and analyzed by nano flow and high flow liquid chromatography coupled to a high-resolution accurate mass Orbitrap-based mass spectrometer. Full-scan polarity switching was used for untargeted profiling, and the AcquireX Deep Scan workflow was applied to support data-dependent MS/MS acquisition in the complex matrix. A SPLASH dilution series was analyzed in triplicate injections to compare analytical response across on-column loads between the two workflows.
RESULTS: At 25 ng on-column, nano flow yielded 1266 total lipid annotations and 835 high-quality annotations, compared with 919 total and 518 high-quality annotations for high flow at 100 ng. Unintentional fragmentation decreased under nano flow conditions by 21%-31% across the representative lipid species evaluated. The use of nano flow allowed for the detection of lower on-column loads across several standards, extending the lower end of the response range by up to 40-fold compared with high flow analyses.
CONCLUSIONS: Nano flow lipidomics improved sensitivity for untargeted analysis by increasing the number of lipid annotations, reducing unintentional fragmentation, and extending the analytical response to lower on-column loads. Together with practical guidance around sample preparation, injection volume, washing, and equilibration, these results support nano flow chromatography as a sensitive and reliable approach for sample-limited untargeted lipidomics.

DOI: https://doi.org/10.1002/rcm.70175
Fa Yi Xue Za Zhi. 2026 Jun 25. pii: 1004-5619(2026)03-0261-08. [Epub ahead of print]42(3): 261-268

[Enzyme Digestion LC-MS/MS Detection of Etomidate, Ketamine, Methamphe‑ tamine and Codeine in Hair].

Mingjin Yang, Meiyun He, Weian DU, Pengfei Mei, Xuelian Cheng, Xin Liu, Yuesen Shi, Hao Jin, Yiling Hu, Meixin He, Ling Chen, Chao Liu.

   OBJECTIVES: To establish a liquid chromatography-tandem mass spectrometry (LC-MS/MS)method based on enzymatic digestion for the rapid qualitative and quantitative detection of drugs in hair.
METHODS: The enzymatic digestion parameters for etomidate, ketamine, methamphetamine, and codeine, including dithiothreitol (DTT) concentration, proteinase K concentration, incubation temperature and digestion time were optimized using controlled-variable experiments. After digestion, hair samples were filtered through a 0.22 μm membrane and separated on a C18 column with a gradient elution using 0.1% formic acid in water and 0.1% formic acid in acetonitrile and analyzed using electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode. After validation, the method was applied to 155 drug-related hair samples and compared with the cryogenic wet-grinding method.
RESULTS: Etomidate, ketamine, methamphetamine, and codeine in hair samples all showed good linearity with their respective linear ranges (R2>0.998 0), with limits of detection (LOD) of 0.005-0.010 ng/mg and limits of quantification (LOQ) of 0.02-0.04 ng/mg. Matrix effects ranged from -12.09% to 8.23%, while the relative standard deviations of intra-day precision and inter-day precision were 2.56%-10.37% and 5.50%-15.11%, respectively. Average recoveries (88.97%-104.05%) met analytical requirements. Results from drug-related hair samples suggested good consistency between enzymatic digestion and cryogenic grinding pretreatment method, while enzymatic digestion demonstrated higher extraction amounts for codeine than cryogenic grinding pretreatment method.
CONCLUSIONS: The established method is simple to operate, highly sensitive, and reproducible, making it suitable for high-throughput hair drug analysis, providing an efficient and reliable analytical method for forensic identification.

Keywords:  LC-MS/MS; drugs; enzymatic digestion method; forensic medicine; hair analysis; toxicological analysis

DOI:  https://doi.org/10.12116/j.issn.1004-5619.2025.350801
Se Pu. 2026 Sep;44(9): 1019-1027

[Determination of glufosinate and its metabolite residues in tea by ultra-high performance liquid chromatography-tandem mass spectrometry coupled with precolumn derivatization].

Rui-Feng Bi, Shi-Hui Fu, Suo-Cheng Deng, Meng Fu, Wei-Wei Zhang, Yu-Hua Song.

  Tea is an important cash crop in China， and pesticide residues in tea products are among the main issues affecting tea exports. Glufosinate （GLU） is a widely used herbicide in tea gardens and its residues in tea samples have raised health concerns. However， there are few reports on analytical methods for the simultaneous determination of GLU and its metabolite residues in tea. Therefore， the development of suitable analytical methods to monitor the content of GLU and its metabolite residues in tea is essential to ensure compliance with the export quality standards of tea products. In this study， a sensitive analytical method was developed for the determination of GLU and its two main metabolites， N-acetyl-glufosinate （NAG） and 3-［hydroxy（methyl）phosphinoyl］propionic acid （MPP）， in tea. The method is based on ultra-high performance liquid chromatography-tandem mass spectrometry （UHPLC-MS/MS） coupled with precolumn derivatization. Tea samples （2.00 g） were extracted with 20 mL of ultrapure water by shaking， and followed by centrifugation. After freezing treatment， aliquots of the extract were centrifuged at 15 000 r/min. Then 200 μL of the supernatant was evaporated to complete dryness using nitrogen blowdown. The resulting residue was derivatized with triethyl orthoacetate （TEOA） at 80 ℃ for 1.5 h， in the presence of acetic acid as the catalyst. The derivatization mixture was evaporated to dryness and reconstituted with methanol. NAG was transformed into the same reaction product as GLU， and therefore quantified together with GLU. The derivatization products were separated on an Agilent ZORBAX Eclipse Plus C18 column （100 mm×2.1 mm， 1.8 μm）. The mobile phase consisted of an aqueous solution of 0.1% （V/V） formic acid （containing 5 mmol/L ammonium formate） as phase A and acetonitrile as phase B. The gradient elution was carried out as follows： 0-0.5 min， 90%A； 0.5-7.5 min， 90%A-80%A； 7.5-8.0 min， 80%A-10%A； 8.0-10.0 min， 10%A； 10.0-10.1 min， 10%A-90%A； 10.1-12.0 min， 90%A. The separated compounds were detected by tandem mass spectrometry with positive electrospray ionization （ESI+） in multiple reaction monitoring （MRM） mode， and stable isotope-labeled internal standards were used for quantitative analysis. Good linearity was obtained in the 0.5-20 μg/L range； the correlation coefficients （r2） were higher than 0.995， the limits of detection were 2.2-5.3 µg/kg and the limits of quantification were 25 µg/kg. For two representative matrices of green tea and black tea， the average recoveries of GLU and MPP spiked at four levels of 0.025， 0.05， 0.1， and 0.5 mg/kg were 83.9%-105.0%. The intra-day precisions （n=5） ranged from 1.9% to 6.9% and the inter-day precisions （n=10） ranged from 2.6% to 10.3%. Furthermore， the developed method was used to detect GLU and its metabolite residues in 34 tea samples， and the positive detection ratio was 26.5%. In summary， the proposed method is simple， reliable， practical， and suitable for determining GLU and its metabolite residues in various types of tea.

Keywords:  3-［hydroxy（methyl）phosphinoyl］propionic acid; N-acetyl-glufosinate; glufosinate; precolumn derivatization; tea; triethyl orthoacetate; ultra-high performance liquid chromatography-tandem mass spectrometry （UHPLC-MS/MS）

DOI:  https://doi.org/10.3724/SP.J.1123.2025.09022
Nat Commun. 2026 Aug 14. pii: 9794. [Epub ahead of print]17(1):

Column switching liquid chromatography dual mass spectrometry system for simultaneous untargeted metabolomics and targeted exposomics.

Yuting Wang, Daidi Hou, Yuan Yuan, Pengwei Guan, Tiantian Chen, Xingyu Guo, Xin You, Xianzhe Shi, Xiaolin Wang, Qi Wang, Xinyu Liu, Guowang Xu.

Exposome-wide association studies (ExWAS) require the detection of metabolites and exposures with diverse chemical properties across wide concentration ranges, a task that typically demands multiple analytical methods. To address this challenge, we develop an integrated column-switching two-dimensional liquid chromatography-dual mass spectrometry (2DLC-dual-MS) system. This system employs a 2DLC setup to sequentially separate polar and non-polar compounds with log P ranging from -8 to 15. The separated fractions are directed via a three-way valve to a high-resolution MS (HRMS) and a triple quadrupole MS (TQMS), enabling simultaneous untargeted metabolome analysis and targeted quantification of 601 exposures. The method is particularly suited for the concurrent analysis of metabolome and exposome in human blood, where their concentrations typically differ by 2-3 orders of magnitude. In a demonstration application on lung adenocarcinoma ExWAS, the system exhibits good stability over more than 300 consecutive injections for both metabolome and exposome analysis, confirming its robustness for ExWAS applications.

DOI: https://doi.org/10.1038/s41467-026-76696-w
J Chromatogr A. 2026 Sep 06. pii: S0021-9673(26)00763-6. [Epub ahead of print]1787 467437

A library of experimental collision cross sections for food, beverage and plant metabolites generated by reversed-phase liquid chromatography coupled to travelling-wave ion mobility and high-resolution mass spectrometry.

Vania Sáez, Fulvio Mattivi, Giorgio Zanoni, Pavel Solovyev, Urska Vrhovsek, Panagiotis Arapitsas.

  Collision cross section (CCS), considered an ion-specific physicochemical property derived from ion mobility spectrometry (IMS), has become a valuable orthogonal descriptor for metabolite characterisation. When coupled with liquid chromatography and high-resolution mass spectrometry, CCS enables a multidimensional analytical approach to address challenging metabolite annotation, particularly for isomeric compounds or when reference standards are unavailable. In food and plant metabolomics, where chemical diversity is vast and reference databases are limited, expanding experimental CCS libraries remains a priority. Here, using reversed-phase liquid chromatography hyphenated with travelling wave ion mobility spectrometry and high-resolution mass spectrometry (RPLC-TWIMS-HRMS), we present a comprehensive library of 597 TWCCSN2 values from 274 standard references, including commercial, non-commercial and in-house isolated compounds relevant to the wine, food and plant metabolome. High intra-and inter-day repeatability was established across 35 metabolites from diverse chemical classes, with 96.5% of the 171 paired measurements showing inter-software agreement within ±2.0% ΔCCS when processed in parallel using two commercial data processing software platforms. Evaluation of five machine learning-based CCS prediction tools against the experimental library revealed up to 68.9% of predicted values within ±3.0%ΔCCS, with chemical class-dependent performance highlighting the importance of continued expansion of experimental CCS resources for confident annotation in metabolomics workflows.

Keywords:  CCS library; Collision cross-section (CCS); Ion mobility spectrometry (IMS); Metabolite annotation; Travelling wave ion mobility (TWIMS)

DOI:  https://doi.org/10.1016/j.chroma.2026.467437
Se Pu. 2026 Sep;44(9): 1028-1037

[Determination of 33 non-steroidal anti-inflammatory drug residues in horse urine by QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry].

Xiao-Nan Zhang, Zhi-Chao Ma, An Liu, Yuan Huang, Xue-Hong Min, Mei Liu, Zheng-Qi Xie, Yan-Song Wei.

  Non-steroidal anti-inflammatory drugs （NSAIDs） are often used to treat horses' injuries and pain due to long-term training and competitions. In equestrian competitions， NSAIDs do not affect the upper limit of a horse's athletic ability， but they can enable the horse to perform close to its maximum capacity by reducing inflammation and pain. This not only affects the competition results， but also fails to ensure the health and welfare of the horses. Therefore， it has become crucial to effectively monitor and control NSAIDs residues during equestrian competition. In this study， a rapid screening and determination method for 33 NSAIDs in horse urine was established using QuEChERS pretreatment combined with ultra performance liquid chromatography-tandem mass spectrometry （QuEChERS-UPLC-MS/MS）. The pretreatment process， chromatographic conditions， and mass spectrometric conditions were also optimized. In brief， the target analytes in 1 mL of horse urine samples were extracted with 5 mL of acetonitrile. During extraction， 100 mg of NaCl was added as a salting-out agent， and the mixture was shaken for 3 min. Subsequently， the extract was purified using a QuEChERS method with 300 mg of anhydrous MgSO4， 40 mg of octadecylsilane-bonded silica （C18）， and 40 mg of primary secondary amine （PSA） as sorbents. After centrifugation， the supernatant was dried under nitrogen and reconstituted. The 33 NSAIDs were separated on an Agilent Poroshell 120 EC-C18 analytical chromatographic column （100 mm×3.0 mm，2.7 μm） with gradient elution using （A） 0.1% formic acid aqueous solution and （B） methanol solution as the mobile phases. The gradient elution program was as follows： 0-1 min， 30%B； 1-3 min， 30%B-60%B； 3-12 min， 60%B-85%B； 12-12.1 min， 85%B-95%B； 12.1-14 min， 95%B； 14-14.1 min， 95%B-30%B； 14.1-17 min， 30%B. Then， the target analytes were determined by UPLC-MS/MS in dynamic multiple reaction monitoring （dMRM） mode with positive/negative ion switching. Quantification was performed using the matrix-matched external standard method. The results showed that the method can rapidly and simultaneously determine the 33 NSAIDs in horse urine. The analytes had good linear relationships within their respective ranges， with correlation coefficients of >0.99. The limits of detection （LODs） and quantification （LOQs） were 0.1-1.0 μg/L and 0.9-5.4 μg/L， respectively. The recoveries of the 33 NSAIDs in horse urine were between 70.8% and 123.8% at three spiked levels of LOQ， 20 μg/L and 200 μg/L. The relative standard deviations of all targeted compounds ranged from 1.9% to 14.8%. The method was applied to 10 actual horse urine samples. The results revealed the presence of three NSAIDs， including ketorolac， lornoxicam and naproxen， with contents ranging from < LOQ to 6.87 μg/L. According to the Equine Prohibited Substances List published by the Federation Equestre Internationale （FEI）， ketorolac and naproxen are controlled medications. They are prohibited for use during competition period， as they may mask symptoms and aggravate clinical conditions. However， they are permitted for use during non-competition times. Lornoxicam is a banned substance and is strictly prohibited for use in horses at any time. The proposed method is simple， efficient and accurate， and is suitable for the simultaneous determination of the 33 NSAIDs residues in horse urine samples.

Keywords:  QuEChERS; horse urine; non-steroidal anti-inflammatory drugs （NSAIDs）; residues; ultra performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS）

DOI:  https://doi.org/10.3724/SP.J.1123.2025.08014
Front Chem. 2026 ;14 1894102

Biomonitoring: a demonstration of the importance of direct analytical methods for the assessment of chemical exposures.

Roy Gerona, Alia Sovereign, Patricia Hunt.

   Introduction: Biomonitoring of commercial endocrine-disrupting chemicals (EDCs) increasingly underpins exposure assessment and risk evaluation, yet most large-scale studies still rely on indirect, enzymatic hydrolysis-based methods whose quantitative performance has not been systematically verified. Here, we describe the development and rigorous validation of a direct liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay using validated standards to simultaneously quantify bisphenol S (BPS), propylparaben (PrP), monobutyl phthalate (MBP), and their major urinary glucuronide and sulfate conjugates in human urine.
Methods: A direct LC-MS/MS assay was developed for the simultaneous quantification of BPS, PrP, MBP and their major urinary metabolites. The method was validated in accordance with U.S. Food and Drug Administration bioanalytical guidelines, including assessments of linearity, accuracy, precision, selectivity, specificity, matrix effects, recovery, and carryover. The validated assay was then used to evaluate the accuracy of a conventional β-glucuronidase-based hydrolysis workflow across a wide concentration range in spiked synthetic urine by comparing indirect measurements with direct totals for each analyte. Method utility in human biomonitoring was demonstrated by analysis of urine samples from 30 pregnant women in their second trimester.
Results: Using isotope-dilution calibration, solid-phase extraction, and negative-ion electrospray multiple reaction monitoring, the method achieved sub-ng/mL limits of detection for all analytes, linear response over 3-4 orders of magnitude, and intra- and inter-day precision and accuracy within contemporary bioanalytical criteria, confirming fitness for trace-level biomonitoring. Indirect, hydrolysis-based measurements closely tracked direct totals for BPS and PrP, but systematically underestimated MBP, with a concentration-dependent negative bias that increased at higher levels, demonstrating that hydrolysis efficiency is analyte-specific and cannot be inferred from surrogate substrates alone. Application of the direct method to archived urine samples from 30 pregnant individuals enabled the first simultaneous resolution of the free and conjugated forms of these three EDCs in a maternal cohort and revealed that glucuronides accounted for the majority of the total urinary burden, with total concentrations exceeding contemporary NHANES estimates.
Discussion: Collectively, these findings show that indirect methods can introduce substantial, analyte-dependent underestimation of internal dose, with implications for exposure misclassification, attenuation of epidemiologic effect estimates, and underestimation of population risk. The data support the position that direct LC-MS/MS quantification of parent and conjugated species, coupled with analyte-resolved assessment of hydrolysis efficiency, should become standard practice in method validation and national biomonitoring programs to ensure accurate exposure assessment for non-persistent EDCs.

Keywords:  LC-MS/MS; bisphenol S (BPS); direct method; endocrine-disrupting chemicals; monobutyl phthalate; propylparaben

DOI:  https://doi.org/10.3389/fchem.2026.1894102
Se Pu. 2026 Sep;44(9): 1010-1018

[Simultaneous determination of three tryptamines in foods by ultra performance liquid chromatography-tandem mass spectrometry coupled with hydrophilic column separation].

Xiao-Lei Liao, Qin Lin, Yue Mei, Hong-Shun Dou, Hui Xu, Yun He, Cheng Pan, Feng-Ling Jiang.

  The illegal addition of substances in ordinary food poses a serious threat to food safety. Therefore， the detection and identification of such additives have long been important research areas in the field of food safety. Especially， illegal additives are showing new trends now， such as emerging functional varieties， new structural derivatives， and clandestine addition practices. Meanwhile， along with the development of online shopping and logistics， new threats pose a substantial challenge to social governance and food safety. In recent years， there are frequent cases of people consuming wild mushrooms containing hallucinogenic tryptamine toxins out of curiosity， and the abuse of tryptamine psychoactive substances also occurs from time to time. Therefore， the development of a robust and sensitive analytical method is necessary for accurately identifying the risks associated with tryptamine psychoactive substances.To address this issue， a novel method based on ultra performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） combined with an isotopic internal standard and solid-phase extraction purification technique was developed for the simultaneous determination of three tryptamines （psilocin， bufotenine and psilocybin） in ten types of ordinary foods. Several optimization procedures were undertaken， involving the chromatographic conditions， mass spectrometric parameters， and sample extraction and purification protocols. The food samples were extracted and centrifuged， followed by purification using a strong cation exchange solid-phase extraction column. The separation was carried out using a Capcell PAK ST （S-5） hydrophilic interaction chromatographic column. The multi-reaction monitoring （MRM） mode was employed for data acquisition in the positive ion mode， whereas isotopic internal standards were used to quantify the three tryptamines. It was verified that the calibration curves of psilocin， bufotenine， and psilocybin exhibited good linearities （R2>0.995） within the range of 0.025-10.0 ng/mL. The limits of detection （LODs） for psilocin， bufotenine and psilocybin were determined as 0.4， 0.5， and 0.6 µg/kg， respectively， while the limits of quantification （LOQs） were determined as 1.4， 1.7， and 1.9 µg/kg， respectively. The LODs and LOQs demonstrate that the method has the ability to detect minute quantities of tryptamines. The recoveries of the tryptamines were 94.3%-113.7% under three spiked levels， with relative standard deviations （RSDs） ranging from 0.4% to 4.9% （n=6）. The consistent and satisfactory recoveries of tryptamines indicate that this method meets the requirements to accurately quantify the target analytes even in a complex matrix. In summary， this newly developed method is rapid， sensitive， accurate， and compliant with relevant regulatory standards； hence， it is suitable for the determination of psilocin， bufotenine and psilocybin in food matrices. As part of the application of this method， a comprehensive investigation was conducted on ten types of actual food samples， including candies， beverages， wines， succade， coffee， health care products， condiments， cooked meat products， spices and hot pot sauce. As a result， out of 100 samples， 14 samples were found to contain bufotenine. Additionally， one sample had a bufotenine concentration of 7.6 mg/kg. By tracing back， it was discovered that the bufotenine in the positive samples was derived from Zanthoxylum armatum DC. or Zanthoxylum Bungeanum Maxim. Subsequently， 12 samples， containing Zanthoxylum armatum DC. and Zanthoxylum Bungeanum Maxim， were collected and processed using the same method， which revealed the bufotenine in all samples with the content ranging from 23.8 to 885.0 mg/kg. At the same time， it was found that the daughter ion scanning mass spectra of the Zanthoxylum Bungeanum Maxim sample were almost consistent with those of the bufotenine standard. Based on this， it can be firmly concluded that bufotenine is naturally present in Zanthoxylum armatum DC. and Zanthoxylum Bungeanum Maxim. In conclusion， the developed method and the discovery of the content of bufotenine in Zanthoxylum armatum DC. and Zanthoxylum Bungeanum Maxim provide a reference framework for future research in the areas of food safety risk assessment， the screening of illegal additives， and food product development.

Keywords:  bufotenine; foods; psilocin; psilocybin; solid phase extraction; ultra performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS）

DOI:  https://doi.org/10.3724/SP.J.1123.2025.08022
PLoS One. 2026 ;21(9): e0357115

Analysis of porphyrins from serum and the benefit of inert biphenyl columns for liquid chromatography separation.

Moritz Unnerstall, Manfred Fobker, Patrick Christian Opitz, Lukas Helmer, Eric Suero Molina, Simone König.

Reversed-phase liquid chromatography (LC) is a major separation technique for porphyrins. We coupled C18-based LC with mass spectrometry (MS) for the detection of protoporphyrin IX (PPIX) in the context of neurosurgery, where it is used as a fluorescence marker for tumor visualisation. Here, we demonstrate advantages of the replacement of the C18 with an inert biphenyl (iBP) column, which improved separation resolution and increased detection sensitivity in LC-MS of six porphyrins (uroporphyrin I, hepta-, hexa-, and pentacarboxyporphyrin I, coproporphyrins I and III) associated with the heme biosynthesis pathway. They are of potential interest as intermediates and side products in our research on 5-aminolevulinic acid-induced fluorescence-guided neurosurgery. Porphyrins consist of conjugated π-systems which interact with aromatic stationary phases such as BP by taking advantage of π-π stacking interactions. Carryover observed with PPIX on endcapped C18 stationary phase was reduced. This improvement was due to the reduction of non-specific adsorption on metallic surfaces from the LC instrument by using inert column hardware combined with the BP stationary phase. Passivation by chemical vapor deposition was shown to reduce non-specific adsorption in the LC system better than methods using mobile phase additives. PEEK tubing in conjunction with the iBP-column provided the best results and shortened run time. Furthermore, we present a Python-based software tool for automated data processing and analyte quantification. This work contributes to our ongoing developments of porphyrin LC-MS in blood and tissue samples from glioma patients.

DOI: https://doi.org/10.1371/journal.pone.0357115
Se Pu. 2026 Sep;44(9): 1048-1058

[Determination of 15 fentanyl analogs and amphetamine-type stimulants in hair by liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry].

Qi Wei, Fu-Hai Su, Xin Zhu.

  Drug abuse is a major global public health problem. Fentanyl analogs and amphetamine-type stimulants （ATS） are widely abused worldwide. Hair analysis can trace drug use history over months. This technique has unique advantages in forensic toxicology. However， its application is limited by a lack of matrix-certified reference materials （CRMs）. At present， the existing CRMs are unable to simultaneously cover both fentanyl analogs and amphetamine-type stimulants. This study established a hair sample preparation method based on a water‑dimethyl sulfoxide‑hydrochloric acid soaking approach， targeting 15 analytes （nine fentanyl analogs and six ATS）. The soaking time was systematically investigated. Drug incorporation into hair reached a maximum at 24 days. A slight decrease was observed at 25 days. This decrease may result from desorption and solvent-induced structural changes in keratin. Therefore， 24 days was selected as the optimal soaking time. Preparation experiments demonstrated that 14 of the 15 drugs were successfully embedded into the hair matrix. This study also applied a dual-platform quantitative strategy for certification. The two platforms were liquid chromatography-tandem mass spectrometry （LC-MS/MS） and gas chromatography-mass spectrometry （GC-MS）. Cross-validation between the two platforms improved the reliability of certified values. Sample pretreatment conditions were optimized using Box-Behnken response surface methodology. Four factors were investigated： extraction temperature， extraction time， liquid-to-solid ratio， and hydrochloric acid concentration. The effects of the four factors on extraction efficiency followed a decreasing order： extraction temperature>extraction time>liquid-to-solid ratio>hydrochloric acid concentration. The optimal extraction conditions were as follows： extraction temperature 40 ℃， extraction time 50 min， liquid-solid ratio 100∶1 （mL/g）， and hydrochloric acid concentration 0.01 mol/L. Method validation was performed according to international guidelines. For LC-MS/MS， the limits of detection （LODs） and quantification （LOQs） were 0.05 pg/mg and 0.25 pg/mg， respectively. For GC-MS， the LODs and LOQs were 0.02 ng/mg and 0.08 ng/mg， respectively. Good linearities were obtained for all 15 drugs. Correlation coefficients （r） were greater than 0.999 for both platforms. Good linearities were obtained for all 15 analytes on both platforms with correlation coefficients >0.999 over the respective concentration ranges Intra-day precisions （n=6） were evaluated as relative standard deviations （RSDs）. Inter-day precision （n=30 over 5 days） was also calculated. For 14 drugs （except amphetamine）， RSD values ranged from 0.2% to 9.4%. All RSDs were below 10%， indicating good repeatability and intermediate precision. Stability of hair extracts was assessed at 1， 24， 48， 72， and 96 h at room temperature. The extracts were stable for at least 96 h when stored at room temperature， with RSDs below 6.0% for LC-MS/MS and below 10% for GC-MS. Recovery tests were performed at three quality control levels （low， medium， high）. For LC-MS/MS， average recoveries ranged from 84.46% to 116.4% （n=3）. For GC-MS， average recoveries ranged from 85.50% to 116.4% （n=3）. All RSDs were below 15%. Matrix effects （MEs） were evaluated by comparing matrix-matched standards with solvent standards. ME values between 80% and 120% （n=3） were observed for both platforms. These results indicate negligible ion suppression or enhancement. Homogeneity of the prepared hair reference material was assessed. The results show that the uniformity of the hair samples is good. The contents of the 14 drugs in the prepared hair samples were determined. For LC-MS/MS， the values ranged from 1.012 ng/mg to 7.830 ng/mg. For GC-MS， the values ranged from 1.087 ng/mg to 7.712 ng/mg. Amphetamine was not detected by either platform， likely due to its high polarity and weak binding to keratin. Most drugs showed good agreement between the two platforms. Relative deviations were below 10% for most analytes. However， methamphetamine showed a deviation of -12%. This may be due to matrix effects in LC-MS/MS. The GC-MS results for methamphetamine were more robust. The dual-platform approach allowed cross-validation and enhanced the reliability of the certified values. In conclusion， a dual-platform method based on LC-MS/MS and GC-MS was successfully applied to certify a new hair matrix reference material. The cross-validation strategy enhances the accuracy and traceability of the certified values. This work provides a valuable tool for quality control in forensic toxicology laboratories. The prepared reference material and validated method will facilitate inter-laboratory comparisons. They will also support the monitoring of drug abuse in forensic and clinical settings.

Keywords:  amphetamine-type stimulants; fentanyl analogs; gas chromatography-mass spectrometry （GC-MS）; hair; liquid chromatography-tandem mass spectrometry （LC-MS/MS）; reference material

DOI:  https://doi.org/10.3724/SP.J.1123.2025.12005
J Chromatogr B Analyt Technol Biomed Life Sci. 2026 Sep 06. pii: S1570-0232(26)00380-6. [Epub ahead of print]1284 125291

N-Alkylpyridinium sulfonates as versatile scout compounds for multi-mode highly targeted metabolomics: Application to Gammarus fossarum.

Remy De Boni, Delphine Arquier, Sophie Ayciriex, Arnaud Chaumot, Davide Degli-Esposti, Olivier Geffard, Arnaud Salvador.

  Although targeted metabolomics using multiple reaction monitoring (MRM) offers high sensitivity, it struggles with multiplexing capacity and retention time drifts. Scout-triggered MRM (stMRM) overcomes these limitations by using reference molecules to dynamically frame the acquisition window. However, establishing comprehensive stMRM assays requires reliable and cost-effective scout compounds that are compatible with multi retention mode of liquid chromatography-mass spectrometry (LC-MS). This study evaluates N-alkylpyridinium sulfonates (NAPS) as versatile exogenous scouts for highly multiplexed stMRM. The chromatographic and ionization behaviours of NAPS were characterised across three stationary phases (reversed-phase C18, F5 and hydrophilic interaction liquid chromatography (HILIC)) in positive and negative electrospray ionization. Due to their zwitterionic structure, NAPS ionised efficiently in both polarities, thereby simplifying dual-polarity acquisitions. Using NAPS as retention-time-independent triggers, we developed a comprehensive multi-mode assay monitoring 559 metabolites. To validate this methodology, we investigated the physiological impact of silver (Ag) exposure on the digestive caeca of the sentinel amphipod Gammarus fossarum. Multivariate analysis revealed metabolic shifts. Mapping these alterations onto species-specific networks highlighted a pronounced disruption of the purine metabolism pathway, characterised by consistent downregulation of xanthine and related intermediate precursors. In conclusion, NAPS are highly effective dual-polarity scout compounds that simplify the multiplexing of stMRM assays. This analytical strategy is a reliable tool for capturing complex molecular responses to environmental stressors in ecotoxicology.

Keywords:  Ecotoxicology; Multi-mode chromatography; N-Alkylpyridinium sulfonate; Scout-trigerred MRM; Targeted metabolomics

DOI:  https://doi.org/10.1016/j.jchromb.2026.125291
Bioinformatics. 2026 Sep 18. pii: btag695. [Epub ahead of print]

Improving Lipid Identification and Quantification: Chromatogram Deconvolution for LC-MS/MS Workflows.

Felix Niedermaier, Denise Wolrab-Frühauf, Robert Ahrends, Dominik Kopczynski.

   MOTIVATION: Lipidomics relies on mass spectrometry-based workflows to identify and quantify complex lipid species. Due to the modular architecture of lipids, including headgroups, backbones, and fatty acyl chains, distinct precursor ions often produce isobaric or identical fragment ions. This problem is amplified in data-independent acquisition (DIA), where wide isolation windows (e.g., 25 Da) allow co-eluting precursors with different m/z values to generate highly chimeric MS/MS spectra. Consequently, fragments originating from multiple precursors, including isobars, isomers, and lipid-class-specific ions, are merged into a single MS/MS spectrum. Current lipid identification strategies often process such chimeric spectra in an uncontrolled manner, assigning them to one or more candidate lipids, thereby increasing false-positive identifications.
RESULTS: Here, we introduce an algorithm that deconvolutes chimeric MS/MS spectra and chromatograms by exploiting their temporal correlation with associated precursor chromatographic profiles, independent of elution peak shape. Using simulated and real experimental lipidomics data, we demonstrate that this approach substantially improves lipid fragment assignment, reduces false-positive identifications, and enables more reliable fragment-level quantification, leading to more robust downstream statistical analyses and biological interpretations.
AVAILABILITY AND IMPLEMENTATION: Source code of the software library: GitLab (Apache 2.0 License): https://gitlab.com/computational-multiomics/mixture-model-deconvolution; Data: Zenodo (Apache 2.0 License): https://doi.org/10.5281/zenodo.21218594.
SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Keywords:  chemoinformatics; chromatogram deconvolution; lipidomics; mass spectrometry; spectral reconstruction

DOI:  https://doi.org/10.1093/bioinformatics/btag695
Angew Chem Int Ed Engl. 2026 Sep 14. e2517884

Emerging Strategies for Comprehensive Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Complex Product and Industrial Matrices.

Friederike Lünne, Theresa Anna Zorn, Alexander Köhrer, Pia Schünemann, Sebastian Kampf, Björn Meermann, David Schaffert.

  The tightening regulatory landscape for per‑ and polyfluoroalkyl substances (PFAS) has created an urgent demand for robust analytical methods and reliable monitoring data to support risk management and regulatory compliance. Consequently, the analytical demands are increasing, and robust and broadly applicable analytical methods are required. This review provides a critical overview of established and emerging analytical methods and techniques for rapid PFAS screening, identification, and quantification of PFAS with a particular focus on complex industrial materials and consumer products. Fluorine-based sum parameter approaches are discussed alongside 19F nuclear magnetic resonance spectroscopy (19F NMR) and gas chromatography mass spectrometry (GC-MS). Emphasis is placed on the decisive role of sample preparation in achieving comparable and reliable results across diverse matrices. In addition to established liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods, untargeted and sum‑parameter approaches are discussed for complementary strategies to address the chemical heterogeneity of PFAS. The adaptability and technical limitations of these methods are critically evaluated with respect to sensitivity, matrix applicability, standardization, and suitability for routine implementation. Overall, this review highlights the strengths and limitations of PFAS analysis methods, identifies remaining methodological gaps, and underscores the need for comprehensive PFAS assessment beyond environmental water matrices.

Keywords:  19F NMR spectroscopy; PFAS analysis; combustion‐ion chromatography; fluorine analysis; sample preparation

DOI:  https://doi.org/10.1002/anie.2517884
Fa Yi Xue Za Zhi. 2026 Jun 25. pii: 1004-5619(2026)03-0240-07. [Epub ahead of print]42(3): 240-246

[Application of Automatic Magnetic Solid-Phase Extraction Instrument in Toxic Substances and Illegal Drugs].

Yawen Xiao, Yaoran Yang, Chongjun Yang, Yan Sun, Yue Chen, Naihan Han, Yuan Meng, Wenjun Wang, Qingshui Ren, Jing Zhu, Tongshu Zhang, Bing Wang, Liyan Zhang.

  Magnetic solid-phase extraction (MSPE) serves as a key pretreatment technique for trace toxic substances and illegal drugs in complex matrices. Its degree of automation and extraction efficiency directly affect the sensitivity and reliability of analytical detection methods. At present, the detection of toxic substances and illegal drugs in forensic science continues to face challenges, including labor-intensive sample preparation, substantial matrix interference, limited enrichment efficiency, and difficulty in controlling operational variability. Conventional solid-phase extraction (SPE) techniques largely rely on manual procedures and are therefore unable to simultaneously meet the requirements for high throughput, accuracy and repeatability in trace analyte analysis. To address these limitations, our team established a novel MSPE method with high enrichment factors based on a self-developed fully automated MSPE instrument (Model HS-401-1). Combined with fluorescence immunoassay, high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and gas chromato- graphy-mass spectrometry (GC-MS), the proposed method was applied to the sample pretreatment and quantitative analysis of toxic substances and illegal drugs in wastewater, blood and urine matrices. The results demonstrated that the extraction instrument could accelerate sample pretreatment, markedly increase enrichment factors, effectively reduce matrix interference, and enhance the response signals of target analytes. The accuracy and precision of the established method met the requirements for trace-level analysis. Practical forensic identification cases verified that the automated MSPE system was able to reduce human-induced operational errors and greatly improve the degree of automation and overall efficiency of the pretreatment workflow. This instrument provides a reliable technical solution for the screening of toxic substances and illicit drugs in forensic science and demonstrates significant academic value as well as promising prospects for widespread application.

Keywords:  automated magnetic solid-phase extraction instrument; forensic medicine; illegal drugs; technology transfer; toxic substances

DOI:  https://doi.org/10.12116/j.issn.1004-5619.2026.360303
Foods. 2026 Aug 24. pii: 2967. [Epub ahead of print]15(17):

Acidified Acetonitrile Extraction and Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry for Multiresidue Determination of 136 Pesticides in Tahiti Lime (Citrus latifolia).

Karolaine da Silva Albarnaz, Juliana Diniz de Barros Kuntz, Luana Floriano, Franciele Fátima Machado, Martha Bohrer Adaime, Renato Zanella, Osmar Damian Prestes.

  The determination of pesticide residues in citrus fruits remains analytically challenging due to their high acidity and complex chemical compositions, which can compromise extraction efficiency and promote significant matrix effects, particularly for acidic compounds. In this study, an acidified acetonitrile-based QuEChERS method was developed and validated for the multiresidue determination of 136 pesticides in Tahiti lime (Citrus latifolia) using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). The proposed approach employs 1% formic acid in acetonitrile and omits the conventional clean-up step, aiming to improve analyte recovery and analytical throughput. Method validation was performed according to SANTE guidelines, demonstrating satisfactory linearity (R2 ≥ 0.99 for all analytes), limits of quantification of 0.01 mg kg-1, and recoveries within 70-120%, with relative standard deviations ≤ 20% for the vast majority of compounds. Notably, the method achieved consistent and reliable performance for 12 acidic pesticides, which are typically problematic in conventional QuEChERS approaches. Application to 22 real samples revealed the presence of 14 pesticide residues, with some compounds exceeding European Union (EU) maximum residue limits. The proposed method provides a simple, efficient, and robust alternative for comprehensive pesticide monitoring in citrus fruits, with particular advantages for the determination of acidic compounds in highly complex matrices.

Keywords:  acidic pesticides; analytical method validation; citrus fruits; food safety; multiresidue analysis

DOI:  https://doi.org/10.3390/foods15172967
J Chromatogr A. 2026 Sep 15. pii: S0021-9673(26)00788-0. [Epub ahead of print]1787 467462

Novel application of reversed-phase high performance liquid chromatography-tandem mass spectrometry for enantioselective determination of cyclaniliprole enantiomers in plant-derived foods.

Mingjin Zhong, Qiuhan Zheng, Junhao Jiang, Yingqiu Zhang, Yilin He, Jinhang Li, Wenjin An, Yu Liu, Qiyang Zhao, Aihua Chen, Jing Li.

  Herein, a rapid and highly sensitive high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was established and validated for the enantioselective determination of cyclaniliprole (CYCP) enantiomers in diverse plant-derived matrices including fruits (citrus, apple), vegetables (cabbage, tomato) and cereals (corn, soybean) matrices. The key innovation of the present work involves the first successful implementation of baseline enantiomeric separation of CYCP under basic reversed-phase conditions. By systematically screening five different chiral stationary phases and critically evaluating both acidic and basic mobile phases, basic conditions utilizing 0.05% diethylamine aqueous solution and acetonitrile were found to be pivotal. This novel basic reversed-phase system on a Superchiral® R-IC column not only afforded baseline separation within 6.5 min but also significantly enhanced both chiral resolution and elution efficiency, markedly reducing retention times compared to acidic conditions. A simple and effective reversed-phase dispersive solid-phase extraction (r-DSPE) procedure, employing multi-walled carbon nanotubes (MWCNTs) as purification sorbents, was optimized for sample preparation, with systematic evaluation of MWCNT type and quantity on purification efficiency and recovery. Comprehensive method validation was performed for linearity, accuracy, precision, sensitivity (LOQ), matrix effects, and stability. Under optimum conditions, mean recoveries for both enantiomers across all matrices ranged from 74.1% to 103.5% with RSDs < 15.2%. Excellent linearity (r ≥ 0.9991) was demonstrated over 0.5-500 μg/L using weighted (1/x) least squares regression. The LOQ was established at 0.005 mg/kg for both enantiomers in all six matrices. Validation data, coupled with successful application to the analysis of real samples confirming method applicability, demonstrate that this robust protocol is suitable for the enantioselective determination of CYCP residues in various agricultural produce, offering a streamlined solution for monitoring chiral pesticides.

Keywords:  Cyclaniliprole; Enantioselective determination; HPLC-MS/MS; Reversed-phase; r-DSPE

DOI:  https://doi.org/10.1016/j.chroma.2026.467462
Drug Metab Dispos. 2026 Aug 26. pii: S0090-9556(26)00662-8. [Epub ahead of print]54(10): 100393

Liquid chromatography-high-resolution mass spectrometry-based integrated strategy combining in silico prediction and molecular networking for metabolite identification of podophyllotoxin in a fatal poisoning case.

Mengyi Wu, Jialin Feng, Junbo Zhao, Huosheng Qiang, Sujing Zhang, Hui Yan, Bin Di, Ping Xiang.

  Podophyllotoxin is an aryltetralin lignan with potent antimitotic and antiviral activities; however, its severe toxicity restricts clinical use to topical application, and systemic exposure to it can result in life-threatening poisoning. However, its metabolic profile remains largely uncharacterized, leaving a critical gap in the biomarkers available for confirming intoxication. Here, we used an integrated nontargeted screening strategy to investigate podophyllotoxin metabolism in post-mortem blood from a rare fatal case of podophyllotoxin poisoning. Two complementary nontargeted screening strategies were established using liquid chromatography coupled to high-resolution tandem mass spectrometry data acquired in both positive and negative ion modes. SyGMa was first used to generate a predicted metabolite list of podophyllotoxin, enabling target analysis against the acquired data. Subsequently, molecular networking was applied to cluster structurally related compounds across specimens based on high-resolution tandem mass spectrometry spectral similarity, enabling visualization and discovery of unknown metabolites and their structural relationships. By integrating these approaches, a total of 11 potential metabolites were identified, including 2 phase Ⅰ metabolites and 9 phase Ⅱ metabolites, of which 5 were previously unreported. Among these, the O-demethylenated and methylated products (m/z 416.1471) are proposed as potential biomarkers for assessing podophyllotoxin exposure. The integrated workflow demonstrated herein facilitates xenobiotic metabolite identification in biological samples, and the characterized metabolites may support future metabolite annotation and exposure assessment through incorporation into mass spectral libraries. SIGNIFICANCE STATEMENT: Human metabolic data for podophyllotoxin remain scarce despite the severe toxicity associated with systemic exposure. By analyzing post-mortem blood from a fatal poisoning case, this study expands knowledge of podophyllotoxin biotransformation and proposes previously unreported metabolites. The results further demonstrate the complementary value of combining in silico prediction with molecular networking for metabolite discovery and annotation, highlighting a practical strategy for characterizing xenobiotic metabolites in limited biological specimens.

Keywords:  High-resolution mass spectrometry; In silico metabolite prediction; Metabolism; Molecular networking; Podophyllotoxin

DOI:  https://doi.org/10.1016/j.dmd.2026.100393
J Sep Sci. 2026 Sep;49(9): e70503

Determination of Enantiomers of Deschloroketamine and Its Metabolites in Wistar Rat Brains.

Natalie Paškanová, Vendulka Hrubá, Peter Frühauf, Bronislav Jurásek, Martin Kuchař, Pavel Řezanka, Michal Kohout.

  Deschloroketamine (DXE) is a dissociative new psychoactive substance whose enantiomers and metabolites may exhibit distinct pharmacological and toxicological profiles. Reliable analytical methods enabling the chiral determination of DXE and its metabolites in biological matrices are thus essential. In this study, we evaluated supercritical fluid chromatography coupled to tandem mass spectrometry (SFC‑MS/MS) and capillary zone electrophoresis with ultraviolet detection (CZE‑UV) for the enantioselective analysis of DXE and its major metabolites in rat brain tissue. SFC using polysaccharide‑based chiral stationary phases provided baseline separation of the hydroxylated and demethylated metabolites, but severe peak distortion of DXE enantiomers prevented their quantification. Therefore, quantitative analysis was performed by CZE employing carboxymethyl‑β‑cyclodextrin as a chiral selector and a high‑sensitivity Z‑shaped detection cell. Analysis of brain tissue samples obtained following high-dose administration revealed near equimolar concentrations of the DXE enantiomers and a higher concentration of (R)-norDXE relative to (S)-norDXE. In this particular case, the combined use of SFC‑MS/MS and CZE‑UV provided a practical workflow for the chiral profiling of DXE and its metabolites in complex biological matrices.

Keywords:  brain tissue; capillary electrophoresis; chiral separation; deschloroketamine metabolites; supercritical fluid chromatography

DOI:  https://doi.org/10.1002/jssc.70503
Anal Methods. 2026 Sep 17.

A QuEChERS-LC-HRMS-based method for the quantification of six sulfonamides and trimethoprim residues in milk.

Christina Kotanidou, Christina-Konstantina Tsamtzidou, Christina Nannou.

The present study describes the development and validation of an analytical method based on QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction and purification with dispersive solid-phase extraction (dSPE) before analysis, followed by liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) for the determination of six (6) sulfonamides and trimethoprim in milk. The validated analytical method demonstrated good validation characteristics, including trueness (recoveries ranging from 73.0% to 114.3% at four fortification levels), linearity (coefficients of determination, R2, above 0.9965 in all cases), and precision (within-laboratory reproducibility below 15.3%). The method exhibited high sensitivity, with limits of quantification (LOQs) ranging from 0.7 to 2.4 µg kg-1, enabling reliable quantification at concentrations below 3% of the maximum residue limits (MRLs) established by European legislation. Matrix effects were generally limited for most analytes, while stability studies confirmed the robustness of the analytical procedure during storage. The validated method was successfully applied to 16 milk samples of different origins and processing types, revealing no quantifiable residues of the target sulfonamides and trimethoprim. The results demonstrate that the proposed QuEChERS/LC-HRMS method provides a reliable, sensitive, and robust analytical tool for the routine monitoring of sulfonamide residues in milk.

DOI: https://doi.org/10.1039/d6ay01587e
STAR Protoc. 2026 Sep 17. pii: S2666-1667(26)00487-9. [Epub ahead of print]7(4): 104834

Protocol for targeted analysis of oxylipins in rat plasma and mouse macrophage samples by high-resolution UHPLC-MS/MS.

Larissa R Diniz, Adriano B Chaves-Filho, Pedro H F Jordão, Rosangela S Santos, Marina T Botana, Johan Kolmert, Ana C A Zucão, Marteinn T Snaebjornsson, Eduardo M Reis, Almut Schulze, Britta Brügger, Craig E Wheelock, Sayuri Miyamoto.

  Oxylipins are bioactive oxygenated fatty acid derivatives that act as signaling mediators in diverse physiological and pathological processes. Here, we present a protocol for the simultaneous analysis of 125 oxylipins in rat plasma and mouse macrophage samples. We describe steps for preparing standards and calibration curves, extracting oxylipins, and performing ultra-high-performance liquid chromatography coupled to high-resolution tandem mass spectrometry (UHPLC-MS/MS). We also detail procedures for using staRoxy, an original R package for oxylipin abundance data analysis. For complete details on the use and execution of this protocol, please refer to Chaves-Filho et al.,1 Kolmert et al.2 and Yapici et al.3.

Keywords:  Mass Spectrometry; Metabolomics; Protocols in Metabolomics and Lipidomics

DOI:  https://doi.org/10.1016/j.xpro.2026.104834