Rapid Communications in Mass Spectrometry最新文献

{"title":"Acoustically Levitated Sample Introduction for GC–MS: A Novel Contactless Approach to Direct Volatile Analysis","authors":"Erhan Akkaya,&nbsp;Ikbal Koyuncu","doi":"10.1002/rcm.10122","DOIUrl":"10.1002/rcm.10122","url":null,"abstract":"<div>\u0000 \u0000 <p>Conventional GC–MS sample introduction methods often involve physical contact, increasing contamination risk and analyte degradation, especially in sensitive matrices. This study introduces a novel, contactless interface using standing-wave acoustic levitation to suspend analytes in mid-air prior to GC–MS analysis. A 28 kHz ultrasonic transducer, powered by a high-voltage amplifier, generates stable levitation nodes inside a custom chamber, enabling droplets and solid particles to remain airborne during volatilization. Volatile analytes are transferred via heated gas mixture directly into the GC inlet. Acetone droplets yielded strong, reproducible <i>m/z</i> 58 ion signals, and real samples like cucumber (<i>Cucumis sativus</i>) skin demonstrated broader applicability. Helium–nitrogen gas mixture was optimized for both levitation stability and ionization efficiency. The system minimized surface contact, preserved sample morphology, and reduced cross-contamination risks. This platform establishes acoustic levitation as a viable sample delivery strategy for GC–MS, offering enhanced cleanliness, reduced sample loss, and novel handling of delicate or trace-level materials. It opens new directions for automation and integration in analytical workflows.</p>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 22","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144814840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Light Stable Isotope Ratios of US Pureed Baby Foods","authors":"Kirsten A. Verostick,&nbsp;Alli Randall,&nbsp;Chris Stantis,&nbsp;Stephannie Covarrubias,&nbsp;Gabriel J. Bowen","doi":"10.1002/rcm.10119","DOIUrl":"10.1002/rcm.10119","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The isotopic composition of foods is useful for verifying origin and provides baseline information for interpreting isotopic data from human tissues in dietary and forensic research. Despite their widespread consumption, baby foods in the United States remain isotopically understudied. This study presents and analyzes an exploratory δ²H, δ¹⁸O, δ¹³C, and δ¹⁵N dataset for pureed baby foods spanning different food types, labeling designations, brands, and geographic purchase locations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Pureed baby food was collected from across the United States, focusing on three widely consumed food types (banana, carrot, and sweet potato, <i>n</i> = 117) across several commercial brands. Cryogenically extracted water and residual dry solids were analyzed to determine the δ²H and δ¹⁸O values of water and δ¹³C and δ¹⁵N values of bulk solids.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We found significant isotopic differences between food types, with bananas having the highest δ²H, δ¹⁸O, and δ¹³C values and carrots the lowest. These offsets persisted across different brands. No significant differences were observed across purchase locations. δ¹⁵N values were significantly higher for bananas and carrots labeled “organic,” and d-excess and δ¹⁸O values in banana and sweet potatoes were significantly higher for foods containing added water.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our dataset documents isotopic patterns in pureed baby foods aligning with expectations related to differences in growing environment, farming practices (e.g., organic), and processing (e.g., added water). This supports the potential utility of stable isotope data for studying and authenticating baby food production and distribution. Although limited in sample size, the absence of geographic isotopic variation, which is consistent with geographic homogenization of the modern “supermarket diet,” suggests isotopic inputs from food to bodies of infants and children consuming these prepared foods depend more on consumer choices than on location. Thus, early childhood isotope data may be more informative for reconstructing diet than residence.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 22","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12335003/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144803030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isotopologue Ratios Identify 13C-Depleted Biomarkers in Environmental Samples Impacted by Methane Turnover","authors":"Janina Groninga,&nbsp;Julius Lipp,&nbsp;Min Song,&nbsp;Kai-Uwe Hinrichs","doi":"10.1002/rcm.10118","DOIUrl":"10.1002/rcm.10118","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The stable carbon isotopic composition (δ¹³C) of individual lipids is of great value in studying carbon cycling. Among those, microbial lipids in sediments impacted by high methane turnover stand out due to their uniquely depleted isotopic fingerprint. However, gas chromatography/isotope ratio mass spectrometry (GC/irMS) is limited to volatile compounds, whereas intact polar lipids require extensive preprocessing, which results in the loss of chemotaxonomic information. Expanding compound-specific isotopic information to intact polar lipids would enhance insights into the microbial turnover of methane.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We performed ultra-high-performance liquid chromatography/electrospray ionization/high-resolution mass spectrometry (UHPLC/ESI/HRMS) to analyze standards of archaeol and lipid extracts from a diverse set of sediment samples of a hydrothermal methane seep system. Using the ratio of the M1 isotopologue over the monoisotopic isotopologue M0, we calculated the δ¹³C values of archaeol and various polar, non-GC-amenable lipids. The δ¹³C values of archaeol obtained via ratios were compared to those measured via GC/irMS.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>δ¹³C values of archaeol determined in natural samples via GC/irMS and the UHPLC/HRMS approach were strongly correlated (<i>R</i>² = 0.94; <i>N</i> = 76–82) across a wide range of δ¹³C values (GC-irMS = −119‰ to −34‰). Biomarkers associated with methane turnover consistently yielded δ¹³C values below −60‰, whereas the δ¹³C values of compounds presumably associated with the photosynthesis-based food web remained above −45‰. UHPLC/HRMS measurements of archaeol standard further indicated that δ¹³C values can be reliably determined across an M0 signal-intensity range of approximately one order of magnitude.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results highlight that the M1/M0 ratio from UHPLC/HRMS measurements can be utilized to evaluate the carbon isotopic fingerprint of non-GC-amenable lipids and to reliably detect lipid biomarkers putatively associated with microbial methane turnover carrying extremely depleted isotopic signatures. This paves the way for a comprehensive exploration of intact lipids associated with microbial methane turnover in environmental samples.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 22","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.10118","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Method of Confirmation and Predictive Metabolomics: A Novel Multidimensional Analytical Framework for Characterizing New Psychoactive Substances","authors":"Anirudha Dixit,&nbsp;Aakanksha Soni,&nbsp;Astha Pandey","doi":"10.1002/rcm.10116","DOIUrl":"10.1002/rcm.10116","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The rapid emergence and structural diversity of new psychoactive substances (NPS) present significant challenges for forensic drug analysis. Existing targeted methods often fall short in accurately identifying novel compounds, increasing the risk of false positives or missed detections. This study aims to address this gap by developing a robust, non-targeted analytical approach capable of confidently screening, identifying, and confirming a broad range of NPS.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Method</h3>\u0000 \u0000 <p>A method was developed using Ultra-Performance Liquid Chromatography coupled with Quadrupole Time-of-Flight Mass Spectrometry (UPLC-QTOF-MS) to analyze four selected NPS: Mephedrone (4-methylmethcathinone), Ephylone, 2C-B, and Methamphetamine. Analytical parameters such as retention time, mass accuracy (±5 ppm), diagnostic fragments, ion ratios, and isotope patterns were evaluated. The method was validated against critical criteria including precision, stability, and reproducibility. The limit of confirmation (LOC) for each analyte was established, and predictive metabolomics were performed to investigate metabolic transformations using bulk powder spiking and spiked urine matrices.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The UPLC-QTOF-MS method demonstrated excellent precision and reproducibility, with consistent retention times and diagnostic fragment ions within acceptable limits as per SANTE and WADA TD2023IDCR guidelines. Mass accuracy remained within ±5 ppm, confirming high analytical performance. The established LOC for all analytes was 50 ng/mL. The study also revealed significant metabolic transformations through predictive metabolomics. Compared to conventional tandem MS techniques, QTOF-MS offered enhanced non-targeted screening capabilities and the advantage of retrospective data analysis.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The validated UPLC-QTOF-MS method provides a powerful, reliable tool for the rapid detection and confirmation of emerging NPS in forensic samples. Its high mass accuracy, ability to perform non-targeted analysis, and support for retrospective interrogation make it a superior alternative to traditional mass spectrometric methods. This approach enhances forensic laboratories' ability to keep pace with evolving drug trends and strengthens the integrity of drug-related investigations.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 22","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Methodological Considerations for the Use of Acid-Based Pre-Treatment Protocols for Carbon and Oxygen Analysis of Tooth Enamel","authors":"Karolina Varkulevičiūtė,&nbsp;Christine Winter-Schuh,&nbsp;Cheryl A. Makarewicz","doi":"10.1002/rcm.10090","DOIUrl":"10.1002/rcm.10090","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Chemical pre-treatment is a common methodological step aimed to remove exogenous materials introduced to archaeological tooth enamel in the burial environment through diagenetic processes. However, some of these methods, involving the use of oxidising reagents such as NaClO, H₂O₂, as well as weak acids like CH₃COOH, have been shown to alter the chemical composition and stable isotope values of enamel. Here, we aim to re-examine the effects of commonly used pre-treatment protocols on bioapatite <i>δ</i>¹³C and <i>δ</i>¹⁸O values, and investigate the relationship between diagenetic alteration and measured isotope values, as indicated by pre-screening using attenuated total reflectance-Fourier transform infrared (ATR–FTIR) spectroscopy.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Modern and archaeological samples were subjected to 10 commonly used pre-treatment protocols that apply NaClO, H₂O₂ and/or CH₃COOH to tooth enamel powders at treatment lengths. Preservation status and diagenetic alteration prior to and after treatment were investigated using ATR–FTIR. <i>δ</i>¹³C and <i>δ</i>¹⁸O values were measured before and after treatment to determine if different wet chemistry protocols induced isotopic shifts.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The results show that all pre-treatment protocols imparted shifts in <i>δ</i>¹³C and <i>δ</i>¹⁸O values of up to ± 1.5‰ in both archaeological and modern samples. Most treated samples display increased crystallinity, likely indicating sample recrystallisation. We suggest that these changes indicate the removal of contamination and diagenetic alteration, and also the dissolution and restructuring of enamel carbonate leading to changes in the in vivo isotope signal.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>We discourage the use of H₂O₂ and NaClO to remove organic matter from samples as it incurs unwanted changes to the enamel structure and carbon and oxygen isotope ratios. We also recommend the use of only short-duration acetic acid treatment protocols to avoid recrystallisation caused by prolonged acid exposure and concomitant unwanted change to in vivo isotope values.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 20","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.10090","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144751289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the Quantitative Performance of Atmospheric Solids Analysis Probe-Mass Spectrometry","authors":"Alisha Henderson,&nbsp;Stephanie Rankin-Turner,&nbsp;James C. Reynolds,&nbsp;Matthew A. Turner,&nbsp;Ashley Sage,&nbsp;David Douce,&nbsp;Mario Thevis,&nbsp;Liam M. Heaney","doi":"10.1002/rcm.10112","DOIUrl":"10.1002/rcm.10112","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Atmospheric solids analysis probe-mass spectrometry (ASAP-MS) is an established ambient ionisation technique that allows for the direct and rapid analysis of samples without chromatographic separation. Consequently, applications that typically benefit from ambient ionisation approaches can achieve improved sample throughput and thus improved potential for in situ testing. Previous reports have contrasted in viewpoints on the ability for ASAP-MS to provide reliable quantitative data. Critically, in-depth data exploring the quantitative capabilities of ASAP-MS are currently lacking.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Here, a series of experiments were performed to assess the quantitative performance of ASAP-MS using a proof-of-concept single analyte (caffeine) approach. Analytical precision, accuracy, linearity and sensitivity were investigated using numerous variables, including sample deposition method (i.e., directly placing the probe into the sample vs. pipetting the sample onto the probe) and deposition volume, as well as the presence of a series of different internal standard approaches.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The data acquired demonstrated that the use of a positive displacement pipette and an isotopically labelled (structure-matched) internal standard provided an optimal approach for quantitative reliability, albeit at levels often below the standards set for traditional chromatography-based quantitative assays. The investigations were performed across a concentration range of 50–5000 ng/mL. Whereas measurable responses were seen across the full range in most approaches, limitations in sensitivity were identified and reduced quantitative performance statistics were noted at concentrations below 1000 ng/mL.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These experiments demonstrate, for the first time, a comprehensive investigation into the quantitative performance of ASAP-MS using caffeine as the example analyte. These data offer insight into the current strengths and limitations of quantitative analyses using ASAP-MS and aim to provide practical recommendations to optimise quantitative approaches using this technique.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 22","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.10112","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144751596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LC–MS Determination of Trichloroethylene Glutathione Conjugation Metabolites in a Parkinson's Disease Mouse Model","authors":"Dan Li,&nbsp;Ling Yan,&nbsp;Thomas Ka-Yam Lam,&nbsp;Zongwei Cai","doi":"10.1002/rcm.10117","DOIUrl":"10.1002/rcm.10117","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rational</h3>\u0000 \u0000 <p>Investigating TCE glutathione (GSH) conjugation metabolites is essential, as these reactive intermediates play a central role in TCE bioactivation and are implicated in organ-specific toxicities, including nephrotoxicity, hepatotoxicity, and neurotoxicity. Characterizing and quantifying these metabolites enhances our understanding of TCE metabolism, supports biomarker discovery, and helps elucidate mechanisms of TCE-induced toxicity.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A robust liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was established for the detection and quantification of three major GSH-related TCE metabolites: S-(1,2-dichlorovinyl)-glutathione (DCVG), S-(1,2-dichlorovinyl)-L-cysteine (DCVC), and N-acetyl-S-(1,2-dichlorovinyl)-L-cysteine (NAcDCVC). Serum samples were obtained from male C57BL/6 mice chronically exposed to TCE (100 ppm in drinking water for 15 weeks).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Calibration curves for all three metabolites demonstrated excellent linearity (<i>R</i>² &gt; 0.998). The method achieved limits of detection (LOD) ranging from 0.0057 to 0.0120 nM, limits of quantitation (LOQ) from 0.0189 to 0.0401 nM, recoveries of 75.9%–115.5%, and inter-assay variation of 0.5%–11.5%. PD model mice exhibited elevated serum levels of DCVG and DCVC, while NAcDCVC levels were significantly reduced.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>This study presents the first comprehensive LC–MS/MS-based quantification of TCE GSH conjugation metabolites in serum, offering high sensitivity, precision, and reproducibility. The observed elevated serum levels of the toxic metabolites DCVG and DCVC, along with the markedly reduced NAcDCVC concentrations in PD mice, provide a critical foundation for future investigations into the mechanistic links between TCE exposure and PD pathogenesis.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 21","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144725400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Methylclostebol Metabolism Discovery by Untargeted Analysis","authors":"G. Barone,&nbsp;L. C. Harps,&nbsp;L. Liu,&nbsp;D. Jardines,&nbsp;M. K. Parr,&nbsp;F. Botrè,&nbsp;X. de la Torre","doi":"10.1002/rcm.10114","DOIUrl":"10.1002/rcm.10114","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>This work introduces an alternative experimental approach by integrating high-resolution mass spectrometry (HRMS) with multivariate statistical analysis for metabolite detection and identification. The integration of these tools maximizes information extraction from data, improving accuracy and reducing the risk of false identifications.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Seven volunteers' urine samples were collected before and after oral administration of 10 mg of methylclostebol (4-chloro-17β-hydroxy-17α-methylandrost-4-en-3-one, ClMT) and assigned to three excretion time intervals. Analyses were carried out on a GC–HRMS system (Agilent 8890 GC coupled with 7250 GC/QTOF), utilizing low-energy electron ionization (&lt; 18 eV) to preserve the native molecular skeleton, thereby simplifying mass spectrum interpretation, with acquisition in full scan mode. Raw data were then processed and subjected to multivariate analysis.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The orthogonal partial least squares-discriminant analysis (OPLS-DA) was employed to emphasize differences among specific sample conditions, and features that significantly contribute to classification in the OPLS-DA can be identified as important biomarkers. Samples from the three excretion intervals demonstrated clear separations, occupying distinct areas within the model's defined space. From this approach, the S-plot displayed seven features identified as biomarkers related to methylclostebol ingestion, comparing their mass spectra with an in-house library of LE-EI mass spectra.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The application of this approach is demonstrated to enhance the identification of new markers related to the intake of prohibited substances in the anti-doping field, such as methylclostebol. Its application proved to be an alternative strategy that allows for gathering a more comprehensive range of information in the antidoping field.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 21","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144716663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of 12 Unknown Photodegradation Impurities of Tunlametinib Capsules Using Liquid Chromatography Coupled With ion Trap/Time-Of-Flight Mass Spectrometry","authors":"Ying Yang,&nbsp;Jiarui Gao,&nbsp;Hongxia Zeng","doi":"10.1002/rcm.10113","DOIUrl":"10.1002/rcm.10113","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>In March 2024, tunlametinib capsules, a Class 1 new drug (referring to active pharmaceutical ingredients and formulations not previously marketed either nationally or globally), were approved in China for treating patients with advanced melanoma and neuroblastoma RAS viral oncogene homologue mutations who experienced disease progression or intolerance to anti-PD-1/PD-L1 therapy. Risk assessment of impurity profiles is essential for drug safety and efficacy in clinical applications. This study characterized impurity profiles in tunlametinib capsules induced by photodegradation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Initial high-performance liquid chromatography coupled with ion trap/time-of-flight mass spectrometry (HPLC/IT-TOF MS) in positive ion mode was first performed to determine the <i>m</i>/<i>z</i> values of protonated ions and predict the formulas of the detected impurities. Subsequent LC-MSⁿ analyses (<i>n</i> = 2–4) of target compounds elucidated comprehensive structural features.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Twelve previously unidentified photodegradation impurities in tunlametinib capsules were characterized using HPLC/IT-TOF MS.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Structural elucidation of 12 previously uncharacterized photodegradation impurities was achieved through HPLC/IT-TOF MS. These findings establish a scientific foundation for refining quality specifications of tunlametinib.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 21","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144716556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In Vitro Metabolism of Metonitazene in Camels: High-Resolution Mass Spectrometric Characterization for Doping Control","authors":"Jahfar Nalakath,&nbsp;Ansar Babu Palathinkal,&nbsp;Rasheed Naduvilakkandy,&nbsp;Ramees Abdulla Vazhat,&nbsp;Praseen Ondern Komathu","doi":"10.1002/rcm.10111","DOIUrl":"10.1002/rcm.10111","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Novel psychoactive substances, especially those within the benzimidazole class such as metonitazene, are powerful psychoactive agents with considerable potential for misuse in both human and animal sports. Implementing a robust detection and monitoring system is crucial to ensure fair competition and welfare of the athletes involved.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>In vitro studies were conducted using camel liver homogenates to investigate the metabolism of metonitazene in camels. The metabolites were analyzed using a Thermo Fisher Orbitrap Exploris LC–MS system. Method validation for qualitative determination was performed using in-house developed methods, while data analysis and metabolite identification were performed using the Compound Discoverer software.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>A total of seven Phase I metabolites of metonitazene were successfully identified. The metabolic transformations were predominantly characterized by dealkylation reactions. These metabolites hold promise as potential markers for the long-term detection of metonitazene in camels for doping control applications.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>This study highlights the effectiveness of advanced high-resolution LC–MS techniques in identifying and characterizing the in vitro metabolites of metonitazene in camels. Considering the high potency and potential for abuse of metonitazene in camel racing, the metabolites identified offer a valuable basis for establishing robust doping control strategies. These results support the development of regulatory frameworks designed to protect animal welfare and uphold the integrity of the sport.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 21","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}