Rapid Communications in Mass Spectrometry最新文献

{"title":"Water Activation by Methyllanthanides: Hydrogen Versus Methane Evolution","authors":"Songpeng Wan, Yu Gong, Xiuting Chen","doi":"10.1002/rcm.10054","DOIUrl":"https://doi.org/10.1002/rcm.10054","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The lanthanide hydrocarbyl complexes often exhibit exceptional performance in organic synthesis, catalytic process, and small molecule activation, and they generally exhibit several valuable differences in reactivity which can be influenced by the metal center and its oxidation state. Decarboxylation of metal carboxylate precursor is a powerful means to obtain multitudinous organometallic complexes which are well suited for gas-phase investigation by employing electrospray ionization mass spectrometry (ESI-MS) experiments in combination with density functional theory (DFT) calculations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The (CH<sub>3</sub>CO<sub>2</sub>)LnCl<sub>3</sub><sup>−</sup> and (CH<sub>3</sub>CO<sub>2</sub>)<sub>2</sub>LnCl<sub>2</sub><sup>−</sup> (Ln = Sm, Eu, and Yb) precursor anions were produced in the gas phase via ESI of LnCl<sub>3</sub> and CH<sub>3</sub>CO<sub>2</sub>Na mixtures in methanol. Collision-induced dissociation (CID) technique was employed to obtain (CH<sub>3</sub>)Ln<sup>III</sup>Cl<sub>3</sub><sup>−</sup> and (CH<sub>3</sub>)Ln<sup>II</sup>Cl<sub>2</sub><sup>−</sup> via fragmentation reactions of lanthanide acetate chloride anions. Activation of water molecule by (CH<sub>3</sub>)Ln<sup>III</sup>Cl<sub>3</sub><sup>−</sup> or (CH<sub>3</sub>)Ln<sup>II</sup>Cl<sub>2</sub><sup>−</sup> via CH<sub>4</sub> or H<sub>2</sub> release was investigated by ion-molecule reaction (IMR) experiments. With the support of DFT calculations, the influences of lanthanide center and its oxidation state were also explored.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>(CH<sub>3</sub>)Ln<sup>III</sup>Cl<sub>3</sub><sup>−</sup> was generated via decarboxylation of (CH<sub>3</sub>CO<sub>2</sub>)LnCl<sub>3</sub><sup>−</sup> (Ln = Sm, Eu, and Yb) upon CID, while (CH<sub>3</sub>CO<sub>2</sub>)<sub>2</sub>LnCl<sub>2</sub><sup>−</sup> underwent consecutive two-step CO<sub>2</sub>/CH<sub>3</sub> or one-step CH<sub>3</sub>CO<sub>2</sub>·and CO<sub>2</sub> losses to give (CH<sub>3</sub>)Ln<sup>II</sup>Cl<sub>2</sub><sup>−</sup>. All three (CH<sub>3</sub>)Ln<sup>III</sup>Cl<sub>3</sub><sup>−</sup> anions spontaneously reacted with H<sub>2</sub>O to form Ln (OH)Cl<sub>3</sub><sup>−</sup> accompanied by methane release, and the reaction extent is generally following as (CH<sub>3</sub>)Sm<sup>III</sup>Cl<sub>3</sub><sup>−</sup> > (CH<sub>3</sub>)Eu<sup>III</sup>Cl<sub>3</sub><sup>−</sup> > (CH<sub>3</sub>)Yb<sup>III</sup>Cl<sub>3</sub><sup>−</sup>. For (CH<sub>3</sub>)Eu<sup>III</sup>Cl<sub>3</sub><sup>−</sup> with H<sub>2</sub>O, there was minor (CH<sub>3</sub>O)EuCl<sub>3</sub><sup>−</sup> produced through hydrogen loss reaction as well. Three (CH<sub>3</sub>)Ln","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 15","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143897190","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":"High-Resolution LC-MS Approach for In Vitro Metabolite Characterisation of Etonitazene in Camels for Enhanced Doping Control","authors":"Jahfar Nalakath,&nbsp;Ibrahim Waseem Nelliyott,&nbsp;Ahmed M. Kadry,&nbsp;Kothandaraman K. Sankar,&nbsp;Parseen OK","doi":"10.1002/rcm.10055","DOIUrl":"https://doi.org/10.1002/rcm.10055","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The misuse of synthetic opioids particularly those from the benzimidazole class such as etonitazene poses significant challenges for doping control in animal sports including camels racing. These substances are powerful psychoactive agents with a high potential for abuse. Therefore, it is essential to implement robust detection and monitoring strategies to ensure fair competition and protect animal welfare.</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 etonitazene. Metabolites were extracted and analysed using a Thermo Fisher Orbitrap Exploris 120 LC-HRMS system, which provides high-resolution and accurate mass detection. Validation on critical parameters were performed using in-house developed methods while data processing and metabolite characterisation were performed using Compound Discoverer software.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Six Phase I metabolites of etonitazene have been identified elucidating the metabolic pathways in camels. The metabolism was mainly characterised by dealkylation and nitro reduction processes. These metabolites hold significant potential as biomarkers for the long-term detection of etonitazene for doping control applications in camels.</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 characterising the in vitro metabolites of etonitazene in camels. Due to its high potency and potential for misuse in camel racing, the identified metabolites serve as a foundation for effective doping control strategies. These findings contribute to improving regulatory frameworks designed to protect animal welfare and maintain the integrity of the sport.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 15","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143897189","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":"Discrimination Factor of Sulphur Stable Isotope Ratios Between Pregnant Fin Whales and Their Foetuses","authors":"Marc Ruiz-Sagalés,&nbsp;Asunción Borrell,&nbsp;Alex Aguilar","doi":"10.1002/rcm.10057","DOIUrl":"https://doi.org/10.1002/rcm.10057","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>In-utero synthesised tissues of mammals have often been used to infer maternal behaviour during gestation. Differences in <i>δ</i>¹⁵N or <i>δ</i>¹³C values between foetal and maternal tissues (foetus–mother discrimination factors) are well established, but they remain uncertain for <i>δ</i>³⁴S values. This study addresses this gap by investigating such discrimination in <i>δ</i>³⁴S values of fin whale muscle (<i>Balaenoptera physalus</i>) and its potential variation throughout gestation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We analysed muscle <i>δ</i>³⁴S values in 11 pregnant fin whales and their respective foetuses. Samples were obtained from individuals feeding off northwestern (NW) Spain during the 1983–1985 summer seasons. Yearday (0–365) and foetal length at the moment of sampling were considered proxies of the gestation stage and their effect on discrimination factors was examined. The <i>δ</i>³⁴S values were determined by continuous flow isotope ratio mass spectrometry.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p><i>δ</i>³⁴S values in foetal and maternal muscle were positively correlated. <i>δ</i>³⁴S values were higher in foetal muscle (M ± SD = 19.2 ± 0.3 ‰) compared to the maternal one (M ± SD = 18.6 ± 0.4 ‰), with a foetus–mother discrimination of Δ³⁴S = 0.59 ± 0.15 ‰. This observed enrichment may be due to differences in isotopic turnover rates, amino acid metabolism, and/or maternal dietary patterns during gestation. The foetus–mother <i>δ</i>³⁴S discrimination values did not change with yearday or foetus length.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These findings are relevant for understanding foetal-maternal <i>δ</i>³⁴S discrimination and drawing ecological inferences from foetal tissues. Further research is needed to understand the mechanisms driving <i>δ</i>³⁴S fractionation under different scenarios.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 14","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.10057","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143879944","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":"Precision Chemotherapy: Optimizing Calibration for Rapid Determination of Blood Methotrexate by Tandem Mass Spectrometry ± Liquid Chromatography","authors":"Dennis J. Dietzen,&nbsp;Connor J. Blair","doi":"10.1002/rcm.10053","DOIUrl":"https://doi.org/10.1002/rcm.10053","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Rapid therapeutic monitoring of high-dose methotrexate (MTX) chemotherapy is essential to avoid toxicity. MTX concentrations are commonly monitored using immunoassays that are limited by narrow dynamic range and metabolite cross reactivity. Mass spectrometry may improve the molecular specificity of MTX analysis but is limited by slow throughput and extensive calibration. In this study, we examined the consequences of eliminating LC from MS/MS and foregoing external calibration to enable rapid determination of MTX.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>MTX (m/z 455 → 308), was assessed using UPLC–MS/MS or flow-injection MS/MS using a six-point external calibration scheme with a single deuterated internal standard, 4-point internal calibration using ¹³C₅, ¹³C₆, ¹³C₁₁, and ¹³C₁₄-MTX, or by single point calibration with the single deuterated internal standard. Accuracy, precision, and resistance to hemolysis, icterus, and lipemia were compared with immunoassay.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Across all six injection/calibration schemes, imprecision ranged from 2.5% to 10% (CV) from 0.05–10 μM. Regardless of calibration scheme, MS/MS ± LC was more resistant to interference from hemolysis and bilirubin than immunoassay. MS/MS ± LC determination of MTX was compared with immunoassay in 81–100 plasma specimens with MTX concentrations ranging from 0.05–81 μM. Intercept estimates all included zero with 95% confidence. Estimates of slopes versus immunoassay for each of the six analytic approaches ranged from 0.88 to 1.09.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Eliminating LC and external calibration enabled rapid, precise, and accurate determination of MTX concentrations in plasma. Minimalist but robust approaches such as these may enable the use of MS for routine MTX determination in time-sensitive clinical circumstances.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 14","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143880117","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":"Cross-Linking Mass Spectrometry of the Antimicrobial Peptides Magainin 2 and PGLa Reveals Heterodimerization in Micellar Medium.","authors":"Emilie Hirschler, Elise Glattard, Nicolas Arnaud, Johana Chicher, Philippe Hammann, Emmanuelle Leize-Wagner, Burkhard Bechinger, Noelle Potier","doi":"10.1002/rcm.10044","DOIUrl":"https://doi.org/10.1002/rcm.10044","url":null,"abstract":"<p><strong>Rationale: </strong>In this study, we applied cross-linking mass spectrometry (XL-MS) to characterize the oligomeric states of a PGLa/magainin 2 mixture and gain insight into the heterodimerization previously suggested in the literature. Both peptides have shown a synergistic enhancement of activity when tested in antimicrobial assays; however, the mechanism of action is still not well understood.</p><p><strong>Methods: </strong>Peptides solutions were prepared in HEPES buffer in the presence of membrane-mimicking DDM detergent micelles or POPE:POPG 3:1 vesicles. Cross-linking experiments were performed using disuccinimidyl suberate (DSS) or disuccinimidyl glutarate (DSG), and MALDI-MS was used to follow the cross-linking performance. Nano liquid chromatography coupled to mass spectrometry was conducted on a Q Exactive Plus orbitrap to achieve linkage sites determination using pLink2 for data interpretation. Trypsin or pepsin digestion was performed for the characterization of intermolecular links.</p><p><strong>Results: </strong>XL-MS performed in a DDM micelle environment provided direct evidence of a specific PGLa/magainin 2 heterodimer, but no other oligomeric states were detected. Monitoring the reaction using MALDI-MS allowed unambiguous characterization of the cross-linked stabilized oligomers and facilitated a rapid optimization of conditions to achieve the best balance between stabilizing complex formation and avoiding unspecific aggregation. Comparison of the cross-linked species in detergent micelles and lipidic POPE:POPG bilayers revealed different behaviors suggesting that interaction between the peptides might occur differently in both membrane-mimicking media.</p><p><strong>Conclusions: </strong>This study revealed that XL-MS was relevant at the peptidomic level. However, the cross-linking workflow had to be adjusted compared to its use in large-scale protein-protein interaction mapping in order to avoid technical bias arising from the rapid nature of the cross-linking reaction.</p>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":" ","pages":"e10044"},"PeriodicalIF":1.8,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143952011","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":"Sonified Signals From a Compact FT-ICR Instrument: A Feasibility Study. I-Data Mapping to an Equal-Tempered Chromatic Scale.","authors":"Patrick Arpino, Michel Heninger","doi":"10.1002/rcm.10047","DOIUrl":"https://doi.org/10.1002/rcm.10047","url":null,"abstract":"<p><strong>Rationale: </strong>Ions trapped within a Penning cell (ICR) travel periodic orbits whose frequencies are dependent on their mass-to-charge ratio and the value of the magnetic field passing through the trap. Fourier transformation (FT-ICR) decomposes the signal induced in the detection circuit by the rotation of the ions in the cell after the application of an excitation signal. The result of this transformation is a set of characteristic frequencies. We were curious to see whether, once lowered by division into the humanly audible domain, they could be converted into musical notes representative of each of the trapped ions.</p><p><strong>Methods: </strong>Three algorithms, using three different kinds of divisors, either constant or variable, were considered, and the resulting reduced frequencies were compared with those of an equal-tempered chromatic scale, retaining notes with the closest frequencies.</p><p><strong>Results: </strong>The method was not specific enough to differentiate observed ions with very close frequencies as is the case for quasi-isobaric ions (ions having the same nominal mass but differing by their exact mass). Only ions with unit mass resolution could be translated into musical notes, and sometimes to the same one, especially at the high-mass end. However, using three-note chords, instead of single notes, different sounds could be attributed to all integer ions from m/z 19 to m/z 299.</p><p><strong>Conclusion: </strong>It is possible to assign musical notes to unit mass resolution ions analyzed in a simple FT-ICR instrument and design simple didactic musical melodies.</p>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":" ","pages":"e10047"},"PeriodicalIF":1.8,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143958592","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":"Examination of Fe and Cu Isotope Variation in Great Apes Using an Optimized Protocol","authors":"Renee D. Boucher,&nbsp;Linda V. Godfrey,&nbsp;Lars Fehren-Schmitz,&nbsp;Paul L. Koch","doi":"10.1002/rcm.10051","DOIUrl":"https://doi.org/10.1002/rcm.10051","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Iron deficiency plagues reproductive-aged women across the world, and blood loss during menstruation is proposed as the driving force. To assess if other factors related to reproduction influence Fe and Cu isotope variation in females, we measured Fe and Cu isotope compositions in the bones of chimpanzees and bonobos.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>To do this, we optimize the protocol for isolating Fe and Cu (and Zn) from phosphate-rich skeletal materials for further analysis via MC-ICP-MS. Then, we address possible Fe and Cu variation sources in non-menstruating apes (<i>n</i> = 26, of which the sex of 10 was obtained by DNA analysis).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The optimized method reduced acid volume by ~14%, and sample preparation time by ~37.5%. We did not find significant sex differences in δ⁵⁶Fe values (Δ⁵⁶Fe_f-m = 0.13‰) or δ⁶⁵Cu values (Δ⁶⁵Cu_f-m = 0.33‰).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Given the similar Δ⁵⁶Fe_f-m values between non-menstruating apes and humans, reproductive investment, instead of menstruation alone, is a key factor that drives Fe deficiency in reproductive-aged women and is important to consider with proxies of iron status. Our optimized protocol provides an effective method for exploring iron status in other mammalian species.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 14","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865916","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":"Stable Isotope Reference Materials and Scale Definitions—Outcomes of the 2024 IAEA Experts Meeting","authors":"Federica Camin,&nbsp;Dinka Besic,&nbsp;Paul J. Brewer,&nbsp;Colin E. Allison,&nbsp;Tyler B. Coplen,&nbsp;Philip J. H. Dunn,&nbsp;Matthias Gehre,&nbsp;Manfred Gröning,&nbsp;Harro A. J. Meijer,&nbsp;Jean-François Hélie,&nbsp;Paola Iacumin,&nbsp;Rebecca Kraft,&nbsp;Bor Krajnc,&nbsp;Steffen Kümmel,&nbsp;Sangil Lee,&nbsp;Juris Meija,&nbsp;Zoltan Mester,&nbsp;Joachim Mohn,&nbsp;Heiko Moossen,&nbsp;Haiping Qi,&nbsp;Grzegorz Skrzypek,&nbsp;Peter Sperlich,&nbsp;Joelle Viallon,&nbsp;Leonard I. Wassenaar,&nbsp;Robert I. Wielgosz","doi":"10.1002/rcm.10018","DOIUrl":"https://doi.org/10.1002/rcm.10018","url":null,"abstract":"<p>The participants of the 12^th International Atomic Energy Agency (IAEA) meeting on stable isotope reference materials reached a consensus, acknowledging the existence and use of two carbon isotope delta scales: the VPDB (Vienna Peedee belemnite) scale and the VPDB-LSVEC (LSVEC - lithium carbonate prepared by H. J. Svec). Conversion models between the two scales can be established and used but introduce uncertainty. A format for isotope delta scale definition was agreed upon and was used to define the two carbon isotope delta scales and the two main oxygen isotope delta scales, VSMOW-SLAP (Vienna Standard Mean Ocean Water–Standard Light Antarctic Precipitation) and VPDB. Confirmation or identification of a second-scale–defining point is still necessary for the nitrogen and sulfur isotope delta scales.</p><p>Efforts are encouraged to improve consistency among laboratories in the isotopic analysis of “non-exchangeable hydrogen” in bulk organic materials and oxygen in carbonates using the phosphoric acid reaction. Additional topics discussed include (1) need for improvement in reference materials for accurate greenhouse gas isotopic analyses; (2) reference materials under production by the IAEA, the US Geological Survey (USGS), and the US National Institute of Standards and Technology (NIST); (3) methods for value and uncertainty assignment of reference materials; and (4) calculation of carbon-13 isotope delta and oxygen-18 isotope delta of CO₂ measured by dual-inlet isotope ratio mass spectrometry.</p>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 14","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.10018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871470","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":"Gas Chromatography–Mass Spectrometry Analysis and Bioactive Potential of Selected Medicinal Plants","authors":"Waheed Khan,&nbsp;Muhammad Saleem Khan,&nbsp;Ghulam Saddiq,&nbsp;Muhammad Zafar,&nbsp;Salman Majeed,&nbsp;Mohamed Fawzy Ramadan,&nbsp;Muhammad Ishtiaq Ali,&nbsp;Nasibakhon Naraliyeva,&nbsp;Trobjon Makhkamov,&nbsp;Zulunov Islom,&nbsp;Aneta A. Ptaszyńska","doi":"10.1002/rcm.10049","DOIUrl":"https://doi.org/10.1002/rcm.10049","url":null,"abstract":"<div>\u0000 \u0000 <p>Plants offer unlimited source of bioactive compounds that have tremendous applications in pharmaceutical industry to find new sources of medicinal plants (MPs) were evaluated. Gas chromatography–mass spectrometry were used to identify the bioactive compounds of selected medicinal plants. Both extracts contained multiple compounds. The most abundant ones were 3,4-dimethyl-1,5-hexadiene-3,4-diol (7.93%), tau-cadinol (5.84%), and adenosine, N6-phenylacetic acid (5.84%) in one extract. In the other extract, the major compounds were 2-methylcumarone (16.92%), 7-methylbenzo[b]furan (14.81%), and (3E,5E)-3,5-octadien-2-one (10.25%). Some of these compounds have antimicrobial, anticancer, and antioxidant properties. Antioxidant tests showed that <i>Solanum nigrum</i> had the highest antioxidant activity (96.59% at 14.4 concentration), followed closely by <i>Artemisia scoparia</i> (96.55% at 13.2 μg/mL), <i>Tribulus longipetalus</i> (94.76% at 13.6 μg/mL), and <i>Mentha longifolia</i>, which had the lowest (81.94% at 18.4 μg/mL), whereas ascorbic acid, the standard, had the highest value (98.34% μg/mL). The antimicrobial properties of four selected MPs were evaluated. The plant <i>T. longipetalus</i> exhibited the highest zones of inhibition (18 and 20.5 mm) against <i>Pseudomonas aeruginosa</i> at concentrations of 12 and 24 mg/mL. The other plants also inhibited various fungi, including <i>Alternaria alternata</i> and <i>Fusarium oxysporum</i>, though to a lesser extent.</p>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 14","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143856773","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":"Buffer 4-Ethylmorpholinium/Acetate: Exploring a New Alternative Buffer for Native Mass Spectrometry","authors":"Darya Hadavi,&nbsp;Che Yee Ng,&nbsp;Yuandi Zhao,&nbsp;Anjusha Mathew,&nbsp;Ian G. M. Anthony,&nbsp;Berta Cillero-Pastor,&nbsp;Eva Cuypers,&nbsp;Tiffany Porta Siegel,&nbsp;Maarten Honing","doi":"10.1002/rcm.10048","DOIUrl":"https://doi.org/10.1002/rcm.10048","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>To perform native mass spectrometry (MS) studies, there are a limited number of volatile and electrospray ionization (ESI)-MS compatible solutions, such as ammonium bicarbonate and ammonium acetate (AA). These solutions could induce the unfolding of proteins due to the formation of CO₂ bubbles or induced acidification during ESI. Hence, it was important to introduce a buffer suitable to preserve the native form of proteins while simulating physiological conditions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The 4-ethylmorpholinium/acetate (4EM/A) buffer was compared to AA for the analysis of proteins and protein complexes with mass ranges from 5 to 103 kDa and isoelectric points (pI) between 3 and 11. The evaluations were conducted by comparing the native-MS profiles, CCS values, arrival time distributions (ATDs), and proteins bioactivities. The human cardiac troponin complex (cTn complex) and its subunit cardiac troponin T (cTnT) were analyzed as proof of the applicability of this buffer for challenging proteins and protein complexes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>4EM/A led to lower charge states compared to AA, supporting the likelihood of preserving protein folding during nano-ESI and in a high vacuum environment of MS. Ion mobility measurements revealed that proteins in 4EM/A exhibit a lower degree of conformational variation compared to AA, suggesting enhanced conformational stability and potential retention of natural-like compactness. Additionally, testing the impact of 4EM/A on bioactivity, lysozyme showed increased biological activity in 4EM/A relative to AA, highlighting the buffer's potential for real-time assessment of protein interaction kinetics and bioactivity. The 4EM/A buffer enabled native-MS analysis of cTnT for the first time.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>We introduced 4EM/A, with pK_a of 7.72/4.76, as a promising buffer for native-MS studies to maintain protein and protein complex bioactivity and conformational integrity.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 14","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.10048","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143852943","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}