Rapid Communications in Mass Spectrometry最新文献

{"title":"Trapped and drift-tube ion-mobility spectrometry for the analysis of environmental contaminants: Comparability of collision cross-section values and resolving power","authors":"Lidia Belova,&nbsp;Noelia Caballero-Casero,&nbsp;Ana Ballesteros,&nbsp;Giulia Poma,&nbsp;Alexander L. N. van Nuijs,&nbsp;Adrian Covaci","doi":"10.1002/rcm.9901","DOIUrl":"10.1002/rcm.9901","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Ion-mobility (IM)–derived collision cross-section (CCS) values can serve as a valuable additional identification parameter within suspect and non-target screening studies of environmental contaminants. However, these applications require to assess the reproducibility of CCS calculations between different IM set-ups. Especially for the comparison of trapped and drift-tube IM (TIMS/DTIM) derived CCS values, data for environmental applications is lacking.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The presented study assessed the bias of TIMS derived CCS_N2 (^TIMSCCS_N2) values of 48 environmental contaminants from three classes in comparison to a previously established DTIM database. Based on two sets of isomeric bisphenols, the resolving power of both systems was compared, addressing the instrumental settings which influence the resolution of TIMS measurements.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>For 91% of the datapoints, bias between ^TIMSCCS_N2 and ^DTCCS_N2 values (latter set as reference) were &lt; 2%, indicating a good inter-platform reproducibility. TIMS resolving power was dependent on the selected mobility window and ramping times whereby a resolution of up to 116 was achieved. Similar resolving power was observed for multiplexed DTIMS data if a high-resolution post-processing step was implemented.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These results provide valuable insights in CCS_N2 reproducibility facilitating database transfer in future TIMS based studies. Knowledge on the influence of acquisition settings on robustness of ^TIMSCCS_N2 calculations and resolving power can ease method development supporting efficient development and reliable identifications of emerging environmental contaminants.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 21","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142091257","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":"Identification, characterization, and in silico ADMET prediction of nirmatrelvir and its degradation products using HPLC-PDA and LC-QTOF-MS/MS","authors":"Matta Ashwin Kumar,&nbsp;Raja Sundararajan","doi":"10.1002/rcm.9896","DOIUrl":"10.1002/rcm.9896","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Nirmatrelvir is a protease inhibitor that is essential for virus replication. Nirmatrelvir is indicated for the management of mild to severe cases of COVID-19 in individuals who are 12 years of age or older. Forced degradation studies of nirmatrelvir were carried out on the drug substance in solid and solution forms, subjecting it to various stress conditions according to International Conference on Harmonisation (ICH) Q1A(R2) and Q1B guidelines. The analytical method was validated as per the ICH Q2(R1) guidelines.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The drug substance (nirmatrelvir) was subjected to hydrolysis (acidic, alkaline, and neutral), thermal, photolytic, and oxidative stress conditions. Five degradation products (DPs) of nirmatrelvir formed under hydrolytic (acidic and alkaline) and oxidative (2,2-azobisisobutyronitrile) stress conditions. These degradation products were identified and separated using reverse-phase HPLC on a phenomenex kinetex C8 column (250 mm × 4.6 mm × 5 μm) with gradient elution. The mobile phase consisted of 0.1% formic acid and acetonitrile, and detection was carried out at a wavelength of 210 nm.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results and conclusions</h3>\u0000 \u0000 <p>Nirmatrelvir and its five DPs were efficiently separated using reverse phase–HPLC. These five DPs were identified and characterized using LC-electrospray ionization (ESI)-Q-TOF-coupled mass spectrometry analysis in the ESI-positive ionization mode. The formation mechanisms of the DPs and the most probable mass fragmentation pathways for both nirmatrelvir and its DPs were elucidated. The developed method demonstrated selectivity, accuracy, linearity, and reproducibility, making it appropriate for quality control of nirmatrelvir and future research studies. Additionally, the physicochemical and Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) properties of nirmatrelvir and its DPs were predicted using ADMET predictor software. The toxicity profile revealed that DP2 and DP3 have teratogenic effects while DP1 and DP3 caused phospholipidosis.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 20","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.9896","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142054342","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":"Identification of active ingredients in Naomaitai capsules using high-resolution mass spectrometry unite molecular network analysis and prediction of their action mechanisms","authors":"Shuang Li,&nbsp;Zhiyan Liu,&nbsp;Haiping Zeng,&nbsp;Jinyu Fu,&nbsp;Mo Sun,&nbsp;Chun Bao,&nbsp;Chenning Zhang","doi":"10.1002/rcm.9898","DOIUrl":"10.1002/rcm.9898","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Although Naomaitai capsule (NMC) is widely used in clinical practice and has a good curative effect for cerebral infarction, its material basis and mechanism of action remain unclear.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>In this study, ultra-high-performance liquid chromatography (UHPLC) coupled with quadrupole Orbitrap MS technology was used to analyse the in vivo and in vitro components of NMC, and the Global Natural Products Social Molecular Networking website was used to further analyse the components of NMC. Next, systems biology approaches were employed to investigate the mechanism of action of NMC. Finally, molecular docking technology was used to verify the network pharmacological results.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>In total, 177 compounds were identified in vitro, including 65 terpenoids, 62 flavonoids, 25 organic acids and 11 quinones. 64 compounds were identified in the blood of mice, and the main active components included ginkgolide C, ginkgolide A, ligustilide, tanshinone IIB, olmelin, emodin and puerarin. The main targets in vivo included TP53, SRC, STAT3, PIK3CA and PIK3R1.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>In conclusion, this study has revealed that NMC acts on multiple targets in the body through various active components, exerting synergistic effects in the treatment of CI. Its mechanism of action may involve inhibiting neuronal apoptosis, oxidative stress and inflammatory responses as well as reducing cerebral vascular permeability and promoting cerebral vascular regeneration.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 20","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142054341","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":"Integrated network pharmacology and GC–MS-based metabolomics to investigate the chemical profile and efficacy of Anemarrhenae Rhizoma and its processed products","authors":"Wenyu Li,&nbsp;Jinhuan Wei,&nbsp;Xi Tian,&nbsp;Huiyi Zhang,&nbsp;Mengxin Yang,&nbsp;Yukun Niu,&nbsp;Qian Zhang,&nbsp;Nan Wang,&nbsp;Yiran Jin,&nbsp;Yingfeng Du","doi":"10.1002/rcm.9893","DOIUrl":"10.1002/rcm.9893","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Anemarrhenae Rhizoma (AR) has been a frequently utilized traditional Chinese medicine (TCM) for an extended period, with its salt-processed variant being a prevalent application form. Contemporary pharmacological investigations have demonstrated that the salt-processed iteration exhibits a multitude of markedly augmented pharmacological properties. However, whether the pharmacodynamic material basis of this change is related to volatile substances remains unclear. The aim of this study was to develop a strategy to screen volatile pharmacodynamic substances in AR and salt-processed AR (SAR).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A comprehensive approach was developed to identify volatile pharmacodynamic compounds by integrating plant metabolomics, target network pharmacology, and molecular docking technology. Plant metabolomics using GC–MS analysis was conducted to identify volatile chemical markers distinguishing between AR and SAR. Subsequently, network pharmacology was utilized to investigate the correlation between chemical markers and associated diseases. Following this, molecular docking technology was utilized to explore the correlation between chemical markers and disease targets, resulting in the discovery of potential quality control markers.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Fifty volatile compounds were isolated and identified in the salt of AR and SAR. The findings from plant metabolomics analysis demonstrated a distinct differentiation, revealing 13 volatile chemical markers that distinguish between AR and SAR. A target (PPARG) associated with diabetes was identified through target network pharmacology analysis. Thirteen volatile components were subsequently chosen as potential quality markers, taking into account their hypoglycemic activity.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The method developed provides a novel strategy for the identification of pharmacophores in AR and SAR, as well as establishing a foundation for the exploration of the volatile differential components and pharmacodynamics in various processed products of TCMs. Additionally, the findings of this study can serve as a theoretical framework for the development and utilization of volatile components in AR and its processed derivatives.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 20","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142054343","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":"Collision cross-section measurements of small molecules via transient decay profiles observed in Orbitrap mass analyzers","authors":"Ziqin Ni,&nbsp;Ricardo Arevalo Jr","doi":"10.1002/rcm.9887","DOIUrl":"10.1002/rcm.9887","url":null,"abstract":"<p>Collision cross section (CCS) of organic compounds can be measured via Fourier transform-based mass spectrometry (MS) by modeling the decay rate of transient signals in the analyzer. Deriving CCS values of low-mass molecules (mass &lt; 2000 Da and CCS &lt; 500 Ų) with Orbitrap MS is challenging due to their high axial frequencies and small absolute variances in cross-sectional profiles. Here, we acquired mass spectra of progressively more complex low-mass analytes using commercial Orbitrap mass spectrometers. The transient signals were processed using Fast Fourier transform (FFT) and short-time Fourier transform (StFFT) to derive decay constants of multiple select ionic species from a single MS full-scan experiment. Decay constants were translated into CCS values using at least two internal standards in the same mass spectrum. Our results suggest target ionic species should have high <i>S/N</i> in order to derive CCS values with ≤<i>0.5%</i> uncertainty. Limitations in the precision of CCS measurements reflect local space charge effects that disturb ion motion in the analyzer. The derived CCS values of polymer like fragments of Ultramark 1621 and small molecules such as individual protonated amino acids can achieve average ±1% error with selection of internal standards across a wide mass range. Future studies need to optimize the strategy to select internal standards in order to improve the precision and accuracy of CCS measurements for small molecules via Orbitrap MS.</p>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 20","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.9887","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142054339","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":"Ion confinement and separation using asymmetric electrodynamic fields in structures for lossless ion manipulations","authors":"Cullen Greer,&nbsp;Zackary R. Kinlein,&nbsp;Brian H. Clowers","doi":"10.1002/rcm.9900","DOIUrl":"10.1002/rcm.9900","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>TW-SLIM ion mobility separations have demonstrated exceptional resolution by leveraging long paths with minimal loss. All previously reported experiments have used electrode surfaces which are mirrored to generate symmetrically opposing electric fields for ion confinement. However, work with other planar ion optics indicates this may be unnecessary. This study explores conditions under which separations may be obtained using a SLIM with asymmetric electric fields.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The asymmetric field configuration was defined by applying a uniform DC potential to all electrodes of the top PCB of a standard TW-SLIM board pair, with no electrode placement modifications. This configuration was simulated in SIMION to assess transmission through the SLIM. A benchtop TW-SLIM instrument outfitted with a Faraday plate detector was modified likewise, so the top PCB had a uniform DC potential applied to all electrodes, while the bottom board was operated normally.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Simulations show full ion transmission for four different <i>m/z</i> ion populations over a range of DC biases applied to the “pusher” board. Likewise, the modified benchtop instrument is capable of transmitting, separating, and cycling ions with minimal losses. The effect of pusher strength on separation quality is explored, and comparisons between the standard and modified SLIM are made with respect to resolving the +2 and +3 charge states of neurotensin ions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>A functional IMS instrument using asymmetric confining fields demonstrates additional field modifications may be a means to achieve additional functionality with limited interruption of the analysis. A TW-SLIM PCB specifically designed as a pusher board would benefit from minimized manufacturing cost, simplifying assembly, reducing drive electronics, and improved field consistency.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 20","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.9900","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142054344","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":"Determination of three ephedrine psychoactive substances in sewage using solid-phase extraction–ultra-performance liquid chromatography–tandem mass spectrometry","authors":"Yiqin Xu,&nbsp;Fang Yang,&nbsp;Hong Ye,&nbsp;Qingqiang Tang,&nbsp;Yanwen Chen,&nbsp;Zhigang Gao,&nbsp;Shuhua Wang,&nbsp;Fang Zhang,&nbsp;Xiaojing Li","doi":"10.1002/rcm.9877","DOIUrl":"10.1002/rcm.9877","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>In recent years, ephedrine psychoactive substances have attracted much attention due to their prevalence in water bodies and potential threat to aquatic ecosystems. Psychoactive substances have been considered as a new type of environmental pollutant due to their unpredictable potential risks to the behavior and nervous system of non-target organisms. A rapid, sensitive, selective, and robust method for the quantification of three ephedrine psychoactive substances in sewage is needed.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>An ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous determination of three ephedrine psychoactive substances in water. The optimal processing conditions were determined by optimizing the chromatography—mass spectrometry and solid-phase extraction (SPE) conditions (e.g., the SPE column, sample pH, washing, and elution), and the treatment conditions were determined; this was achieved via positive ion scanning in multiple reaction monitoring mode. Poly-Sery MCX was selected as the extraction column, with samples loaded at pH 3. And 4-mL solution of 2% formic acid (FA) aqueous solution was used as the eluent; the target compounds were eluted with 5 mL of 5% NH₄OH in acetonitrile (ACN) solution. The best results were obtained when the residue was resolubulization in ACN after nitrogen evaporation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The developed UPLC-MS/MS showed a good linear relationship in the range of 0–50.00 μg/L, with determination coefficients (<i>R</i>²) greater than 0.9990. The detection limit and quantitation limit were 0.05–0.10 and 0.20–0.50 μg/L, respectively. Recovery rates of the target compounds in blank sewage at three different concentrations ranged from 92.37% to 106.31%, with relative standard deviations (RSDs) of 0.77%–4.83% (n = 7).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This method has been successfully applied to the analysis of surface water and domestic sewage, and the samples were processed stably, indicating that the method is practical for the determination of ephedrine psychoactive drugs in water bodies.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 20","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142054340","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":"Machine learning methods for compound annotation in non-targeted mass spectrometry—A brief overview of fingerprinting, in silico fragmentation and de novo methods","authors":"Francesco F. Russo,&nbsp;Yannek Nowatzky,&nbsp;Carsten Jaeger,&nbsp;Maria K. Parr,&nbsp;Phillipp Benner,&nbsp;Thilo Muth,&nbsp;Jan Lisec","doi":"10.1002/rcm.9876","DOIUrl":"10.1002/rcm.9876","url":null,"abstract":"<p>Non-targeted screenings (NTS) are essential tools in different fields, such as forensics, health and environmental sciences. NTSs often employ mass spectrometry (MS) methods due to their high throughput and sensitivity in comparison to, for example, nuclear magnetic resonance–based methods. As the identification of mass spectral signals, called annotation, is labour intensive, it has been used for developing supporting tools based on machine learning (ML). However, both the diversity of mass spectral signals and the sheer quantity of different ML tools developed for compound annotation present a challenge for researchers in maintaining a comprehensive overview of the field.</p><p>In this work, we illustrate which ML-based methods are available for compound annotation in non-targeted MS experiments and provide a nuanced comparison of the ML models used in MS data analysis, unravelling their unique features and performance metrics. Through this overview we support researchers to judiciously apply these tools in their daily research. This review also offers a detailed exploration of methods and datasets to show gaps in current methods, and promising target areas, offering a starting point for developers intending to improve existing methodologies.</p>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 20","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.9876","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142046045","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":"Use of stable isotope combined with intact cell lipidomic by routine MALDI mass spectrometry analysis for rapid drug susceptibility assay in mycobacteria","authors":"Bosco Cheong,&nbsp;Wenhao Tang,&nbsp;Markus Kostrzewa,&nbsp;Gerald Larrouy-Maumus","doi":"10.1002/rcm.9888","DOIUrl":"10.1002/rcm.9888","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Rapid, accurate, and easy-to-perform diagnostic assays are required to address the current need for the diagnosis of resistant pathogens. That is particularly the case for mycobacteria, such as the human pathogen <i>Mycobacterium tuberculosis</i>, which requires up to 2 weeks for the determination of the drug susceptibility profile using the conventional broth microdilution method. To address this challenge, we investigated the incorporation of deuterium, the stable isotope of hydrogen, into lipids as a read out of the drug susceptibility profile.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Deuterium is incorporated into newly synthesized proteins or lipids in place of hydrogen as bacterial cells grow, increasing the mass of the macromolecules, which can then be observed via matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). As proof-of-concept, we used the non-pathogenic <i>Mycobacterium smegmatis</i> mc²155 strain, which is susceptible to the aminoglycoside antibiotic kanamycin, and <i>M. smegmatis</i> mc²155 containing the empty vector pVV16, which is kanamycin-resistant. Bacteria were incubated in a culture medium containing 50% of deuterium oxide (D₂O) and either 1 or 2 times the minimal inhibitory concentration (MIC₅₀) of kanamycin. Lipids were then analyzed using the MBT lipid Xtract matrix combined with routine MALDI mass spectrometry in the positive ion mode to evaluate the changes in the lipid profile.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Using this approach, we were able to distinguish susceptible from resistant bacteria in less than 5 h, a process that would take 72 h using the conventional broth microdilution method.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>We therefore propose a solution for the rapid determination of drug susceptibility profiles using a phenotypic assay combining D₂O stable isotope labelling and lipid analysis by routine MALDI mass spectrometry.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 20","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.9888","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142046049","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":"Thermal electron attachment to halogenated silanes in the gas phase","authors":"Bartosz Michalczuk,&nbsp;Peter Papp,&nbsp;Dušan Mészáros,&nbsp;Barbora Stachová,&nbsp;Ladislav Moravský,&nbsp;Štefan Matejčík,&nbsp;Wiesława Barszczewska","doi":"10.1002/rcm.9897","DOIUrl":"10.1002/rcm.9897","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Silane derivatives play a crucial role in industrial plasma processes for the fabrication of various electronic devices such as lighting devices, solar cells, and displays. Accurate quantitative data are essential for modeling technological plasmas. This study reports the rate coefficients (k) and activation energies (E_a) for thermal electron attachment to Si₂Cl₆, Si (CH₃)₃CHF₂, and SiCl (CH₃)₂Si(CH₃)₃, which are key parameters for understanding the underlying processes in plasmas. The results obtained for other silane derivatives were also analyzed and discussed.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The measurements were conducted using the pulsed Townsend technique. In this technique, electrons generated by a laser under an electric field travel to the anode, inducing a charge on it. In the presence of a scavenger gas, electrons are captured, leading to a decrease in the rate of charge increase over time. The kinetic parameters were deduced from the shape of the pulse. The G4 method was used to obtain bond dissociation energies (BDEs).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>This study determined the kinetic parameters for thermal electron attachment to Si₂Cl₆, Si (CH₃)₃CHF₂, and SiCl (CH₃)₂Si(CH₃)₃ for the first time. The rate coefficients at 298 K were found to be 2.17 ± 0.04 × 10⁻⁹cm³s⁻¹, 2.01 ± 0.09 × 10⁻¹²cm³s⁻¹, and 8.05 ± 0.07 × 10⁻¹²cm³s⁻¹, respectively. The corresponding activation energies were determined to be 0.37 ± 0.04 eV, 0.29 ± 0.03 eV, and 0.21 ± 0.01 eV for Si₂Cl₆, Si (CH₃)₃CHF₂, and SiCl (CH₃)₂Si(CH₃)₃, respectively. The experiment was conducted over the temperature range of 298–378 K.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The findings of this study provide significant new insights into fundamental parameters such as rate coefficients and activation energies for thermal electron capture by chlorinated and fluorinated silane derivatives. These data contribute to advancing our understanding of thermal electron interactions with chlorosilanes, which can be utilized for controlling important species in the plasmas of various modern technologies.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"38 20","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142046048","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}