Rapid Communications in Mass Spectrometry最新文献

{"title":"Covalent Organic Framework Nanofilm-Assisted Laser Desorption Ionization Mass Spectrometry for Rapid Screening of Parabens in Personal Care Products","authors":"Wenjun Zheng,&nbsp;Jingjing Yan,&nbsp;Yingxue Jin,&nbsp;Zian Lin,&nbsp;Zongwei Cai","doi":"10.1002/rcm.9987","DOIUrl":"10.1002/rcm.9987","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rational</h3>\u0000 \u0000 <p>People are widely exposed to parabens in their daily life, but parabens are endocrine disrupting chemicals that pose a threat to human health. Therefore, establishing a rapid screening method to enhance monitoring of parabens is necessary. Herein, a covalent organic framework (COF) nanofilm-assisted laser desorption ionization mass spectrometry (LDI-MS) method was established to screen parabens in personal care products (PCPs).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>TAPB-TFPB-COF nanofilm was synthesized on indium tin oxide (ITO) glass and used as LDI-MS substrates. To observe the practicability of TAPB-TFPB-COF nanofilm-assisted LDI-MS, the results of this method for analyzing small molecules such as parabens, estrogens, and bisphenols were compared with those of the conventional organic matrix 9-aminoacridine (9-AA), and the reproducibility and detection limit were further verified. Finally, the method was applied to screen parabens in PCPs.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>TAPB-TFPB-COF nanofilm-assisted LDI-MS analyzed small molecules such as parabens, estrogens, and bisphenols with higher mass spectral signals and cleaner mass spectral backgrounds compared with 9-AA. Meanwhile, the method analyzed methylparaben (MeP) with high reproducibility (RSD = 6.96%) and low detection limit (1.64 μM) and performed well for rapid screening of parabens in PCPs.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>TAPB-TFPB-COF nanofilm-assisted LDI-MS for analyzing small molecules such as parabens, estrogens, and amino acids offered the advantages of rapid analysis, a clean background, and good reproducibility. The method was successfully applied to detecting parabens in PCPs, demonstrating the practical utility of LDI-MS based on TAPB-TFPB-COF nanofilm for analyzing parabens in complex samples.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 7","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142942086","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":"Guidelines for Accurate and Precise Stable Isotope Analysis of Calcite, Dolomite, and Magnesite Using a Carbonate Device for Continuous Flow-Isotope Ratio Mass Spectrometry (CF-IRMS)","authors":"Soujung Kim,&nbsp;Sang-Tae Kim,&nbsp;Martin Knyf","doi":"10.1002/rcm.9958","DOIUrl":"10.1002/rcm.9958","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Carbonate minerals are one of the most popular samples for an automated sample preparation system for CF-IRMS, such as GasBench II and iso FLOW, but no standardized analytical protocols exist. This study gives guidelines on optimal analytic conditions for carbon and oxygen isotope analysis of Ca–Mg carbonates when using the carbonate–phosphoric acid reaction method.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Calcite (CaCO₃–McMaster Carrara), dolomite (CaMg(CO₃)₂–MRSI Dolomite), and magnesite (MgCO₃–ROM Brazil Magnesite) with two grain size fractions (&lt; 74 and 149–250 μm) were reacted with 103% (specific gravity of 1.92) phosphoric acid under He atmosphere in 12-mL borosilicate glass vials to examine the full <i>δ</i>¹³C and <i>δ</i>¹⁸O evolution of acid-liberated CO₂ for an extended reaction time of up to 12–30 days at 25°C and up to 3–7 days at 72°C.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>At 25°C, the optimal reaction time of calcite is 1 day for both grain size fractions while the optimal reaction time of 2–10 day is suggested for dolomite with a grain size of &lt; 74 μm. At 72°C, 30-min to 12-h or 45-min to 12-h reaction is optimal for calcite with &lt; 74-μm or 149- to 250-μm grain size fraction, respectively, whereas dolomite requires 12-h to 1-day reaction for both grain size fractions. The only optimal condition for magnesite is 6–7 days of reaction with &lt; 74-μm grain size at 72°C.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>To determine precise and accurate <i>δ</i>¹³C and <i>δ</i>¹⁸O values of a carbonate mineral using the carbonate–phosphoric acid reaction method, an optimal reaction time must be assessed for a given analytical condition to avoid nonequilibrium isotope effects and unnecessary oxygen isotope exchange of acid-liberated CO₂ in the carbonate reaction vessel. Our experimental result provides a guideline for the accurate and precise stable isotope analysis of Ca–Mg carbonate minerals.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 5","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11715619/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142942085","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":"LCMS Detection and Characterization of In Vitro Metabolites of Isotonitazene, a Targeted Strategy for Novel Psychoactive Substance Control in Camel Racing","authors":"Jahfar Nalakath,&nbsp;Rasik P. Thacholil,&nbsp;Ahmed Kadry,&nbsp;Shamil P,&nbsp;O. K. Praseen","doi":"10.1002/rcm.9982","DOIUrl":"10.1002/rcm.9982","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The use of benzimidazole-class novel psychoactive substances has significantly increased worldwide raising concerns about potential misuse and doping in animal sports such as camel racing. Understanding the metabolism of these substances is critical for developing reliable detection methods to ensure fair competition and animal welfare.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p><i>In vitro</i> studies were conducted using homogenized camel liver samples to replicate metabolic processes. Metabolites were extracted and analyzed with a Thermo Fisher Orbitrap Exploris LCMS system. The acquired data were processed using the Compound Discoverer software for accurate detection and characterization of the metabolites.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Through <i>in vitro</i> investigation, we have successfully identified nine metabolites in camels, which provide valuable insights into their metabolic pathways. The primary pathways for the formation of phase I metabolites were dealkylation and hydroxylation; the characterized metabolites can be used for long-term detection of the presence of isotonitazene.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The study employed advanced high-resolution accurate mass LC–MS techniques to detect and identify the <i>in vitro</i> metabolites of isotonitazene in camels. Isotonitazene is a highly active psychoactive substance with significant potential for abuse, particularly in racing contexts. These findings are crucial for developing effective doping control strategies, which will improve regulation and monitoring in camel racing events and promote animal welfare.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 7","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142930187","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":"Metabolomics Analysis Using Chromatography–Mass Spectrometry to Investigate the Mechanism of Cyclosporine in the Treatment of Aplastic Anemia","authors":"Ming-xin Guo,&nbsp;Lin Wan,&nbsp;Xiang Sun,&nbsp;Xi-han Zhou,&nbsp;Wen-tong Fang,&nbsp;Zhang-zhang Sun,&nbsp;Zhi-qiang Hu,&nbsp;Li-li Xue","doi":"10.1002/rcm.9968","DOIUrl":"10.1002/rcm.9968","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>The aim of this study was to use metabolomics techniques to detect differential metabolites in the plasma of patients with aplastic anemia (AA). We explore important biomarkers and potential pathways in cyclosporine A (CsA) in the treatment of AA.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Plasma samples from five patients with AA before and after treatment and plasma samples from five healthy people were collected and analyzed by liquid chromatography–mass spectrometry and gas chromatography–mass spectrometry. Multivariate statistical methods were employed to screen for differential compounds, followed by enrichment analysis of the differentially metabolites.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The experimental samples showed good stability and reproducibility. A total of 167 differential metabolites, including phospholipids, amino acids, and saturated or unsaturated fatty acids, were identified between AA patients and healthy individuals. Enrichment analysis of differential metabolites revealed the involvement of pathways such as pyrimidine metabolism, galactose metabolism, pantothenate and CoA biosynthesis, and forkhead box transcription factors signaling. A total of 26 differential metabolites were identified between AA patients and stable patients after treatment. Enrichment analysis of these metabolites showed the involvement of pathways such as pyrimidine metabolism, linoleic acid/<i>α</i>-linoleic acid metabolism, pantothenate and CoA biosynthesis, and beta-alanine metabolism.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Significant differences in metabolites were observed between AA patients and healthy individuals, suggesting that immune-related and energy metabolism pathways may be key targets in AA treatment. CsA intervention in AA may be achieved through the regulation of immune-related metabolic pathways.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142930185","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 Active Compounds in Sanhuang Shu'ai Decoction for the Management of Ulcerative Colitis: A UHPLC-MS Study","authors":"Amei Liu,&nbsp;Muxiao Zhong,&nbsp;Zhenglan Han,&nbsp;Yuxiang Yan,&nbsp;Dengke Zhang,&nbsp;Xiaoying Wang,&nbsp;Mingjun Wang,&nbsp;Yidan Zou,&nbsp;Jingping Zhang","doi":"10.1002/rcm.9976","DOIUrl":"10.1002/rcm.9976","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>The effectiveness of Sanhuang Shu'ai decoction (SSD), a traditional Chinese medicine used to treat diarrhea and colitis, especially ulcerative colitis (UC), is not well understood regarding how its chemical components work.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>This research used ultra-high-performance liquid chromatography (UHPLC)–tandem mass spectrometry (MS), network pharmacology, and molecular docking to understand the active substances and potential mechanisms of SSD in treating UC.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>UHPLC and MS analyses identified 710 active components in SSD extracts (ZYTQY) and 387 in SSD-containing serum (HYXQ), with 35 active compounds found in both ZYTQY and HYXQ and 67 active compounds from SSDD (SSD compound obtained directly from the database), along with 6 metabolites that may be key components in its function. Subsequently, we used PubChem, DrugBank, and TTD to identify 108 potential targets from SSDD, and 27 hub genes were found by constructing the PPI network. GO and KEGG pathway analyses confirmed that SSDD may be effective in treating UC through the PI3K/AKT and HIF-1 signaling pathways. The pathway analysis of 4 metabolites in SSD highlights the continued importance of the PI3K/AKT pathway. Molecular docking and simulations indicate that baicalein, oroxylin A, quercetin, and wogonin may aid in treating UC by regulating the MAPK3 and NFKB1 genes. Baicalein interacts with several specific targets, including EGFR, MAPK1, MAPK3, NFKB1, PTGS2, and TP53.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>SSD treats UC through various compounds and pathways targeting multiple areas, whereas baicalein specifically promotes intestinal repair in UC by modulating EGFR-PI3K/AKT/NFκB, EGFR/PI3K/AKT-/TP53, and EGFR/PI3K/A KT/MAPK signaling pathways.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142908810","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":"FREDA: A Web Application for the Processing, Analysis, and Visualization of Fourier-Transform Mass Spectrometry Data","authors":"David J. Degnan,&nbsp;Daniel M. Claborne,&nbsp;Amanda M. White,&nbsp;Sarah M. Akers,&nbsp;Natalie M. Winans,&nbsp;Yuri E. Corilo,&nbsp;Clayton W. Strauch,&nbsp;Vanessa L. Bailey,&nbsp;Lee Ann McCue,&nbsp;Kelly G. Stratton,&nbsp;Lisa M. Bramer","doi":"10.1002/rcm.9980","DOIUrl":"10.1002/rcm.9980","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The high-resolution measurement capability of Fourier-transform mass spectrometry (FT-MS) has made it a necessity for exploring the molecular composition of complex organic mixtures, like soil, plant, aquatic, and petroleum samples. This demand has driven a need for informatics tools to explore and analyze FT-MS data in a robust and reproducible manner.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>FREDA is an interactive web application developed to enable spectrometrists to format, process, and explore their FT-MS data without the need for statistical programming expertise. FREDA was built to explore outputs from a molecular identification tool, like CoreMS, and provide a suite of methods to filter data, compute chemical properties of peaks, statistically compare samples and groups of samples, conduct exploratory data analysis, and download the results with a report detailing all steps conducted.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>To demonstrate the utility of FREDA, an example analysis was conducted using FT-MS data from a soil microbiology study of samples collected in two different soil depths at the Sphagnum bog forest north of Grand Rapids, Minnesota. Differences between the two depths are observed using Kendrick, Gibbs free energy, and van Krevelen plots. G-tests are used to quantify a significant difference between the groups. All analyses and plotting are conducted using only the FREDA application.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>FREDA is an open-source and readily available web application that allows users to explore and make statistically valid conclusions about their FT-MS data. The application is available online (https://map.emsl.pnnl.gov/app/freda) with a tutorial web series (https://youtu.be/k5HLE2kNSBY?si=yB6sGoyvzxrFf5MP) and freely accessible code on Github (https://github.com/EMSL-Computing/FREDA).</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 7","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11684152/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142908813","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":"A Doped Surface Ionization Method for Ion Mobility Spectrometry","authors":"Jianhua Lin,&nbsp;Xiaoguang Gao,&nbsp;Jian Jia,&nbsp;Xiuli He","doi":"10.1002/rcm.9974","DOIUrl":"10.1002/rcm.9974","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Exhaled breath can be used for early warning of disease, with organic nitrogen compounds, including triethylamine (TEA), being linked to various medical conditions. Surface ionization ion mobility spectrometry (SI-IMS) facilitates the direct detection of TEA in exhaled breath. However, the presence of multiple ionization products of TEA poses challenges for both quantitative and qualitative analyses.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A doped surface ionization (DSI) method consisting of surface ionization of dopants and gas-phase reaction of samples was proposed, and TEA was detected when combined with an ion mobility spectrometer. TEA at different concentrations and spiked by human breath was detected to evaluate the method's properties.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>TEA with concentrations from 5.99 to 30.50 ppb and a relative humidity of 80% was detected. The peak intensity of the protonated TEA ions demonstrated a linear correlation with concentration, yielding a fitted correlation coefficient of <i>R</i>² = 0.94. A standard deviation less than 0.066% was obtained with 10 replicate analyses of 29.92 ppb TEA, and the recovery rate of the sample was 93.57%.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The SI-IMS based on the DSI method has the advantages of excellent selective ionization, high accuracy and sensitivity, and remarkable repeatability for detecting TEA. It is a promising method for detecting specific organic nitrogen compounds in exhaled breath.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142908807","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":"Comprehensive Optimization of Packing Parameters for Hydraulic-Packed Capillary Columns","authors":"Chunqiu Hu,&nbsp;Hang Fu,&nbsp;Lulu Wang,&nbsp;Yuan Gao,&nbsp;Ruidong Li,&nbsp;Zhen Li,&nbsp;Shuai Li,&nbsp;Xiaowang Xie,&nbsp;Chongxi Ren,&nbsp;Fang Guo,&nbsp;Minjia Tan,&nbsp;Linhui Zhai","doi":"10.1002/rcm.9966","DOIUrl":"10.1002/rcm.9966","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The performance of the capillary column directly impacts the separation efficiency of complex sample in liquid chromatography–mass spectrometry–based proteomics studies. The hydraulic packing system offers an effective solution by reducing packing time and expediting the preparation process of column preparation. However, its operational complexity and strict parameter regulation requirements hinder efficient application.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>This study developed an innovative device for the hydraulic capillary column packing, followed by a systematic optimization and evaluation of crucial parameters such as packing pressure, magnetic stirring rate, concentration of solid-phase material, and choice of packing solvent in the capillary column packing process.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The comprehensive evaluation of the prepared capillary columns showed that the hydraulic packing method enabled rapid and large-scale preparation, while also demonstrating exceptional stability and reproducibility.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The proposed hydraulic capillary column packing strategy in this study holds theoretical and practical implications for advancing the technology of column preparation, enhancing separation efficiency, and expanding the depth of analysis in proteomics research.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 7","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142908812","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":"The Site of Protonation Affects the Dissociation of Protonated α- and β-Pinene Ions","authors":"Edgar White Buenger,&nbsp;Paul M. Mayer","doi":"10.1002/rcm.9978","DOIUrl":"10.1002/rcm.9978","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>In electrospray ionization and atmospheric pressure chemical ionization, the protonation site directly guides the ion's dissociation. But what if the site of protonation is ambiguous? In this study, we explored the unimolecular reactions of protonated α- and β-pinene ions with a combination of tandem mass spectrometry and theory. Each has multiple potential protonation sites that influence their chemistry.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Atmospheric pressure chemical ionization was employed to form the protonated pinene isomers. The unimolecular chemistry of these ions was explored with a Waters Ultima triple-quadrupole mass spectrometer using energy-resolved collision-induced dissociation with argon collision gas. Reaction mechanisms were calculated with CBS-QB3 single-point energy calculations on B3LYP/6-311+G(d,p) optimized structures.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The two main dissociation reactions in each ion lead to the loss of neutral propene and isobutene. Both ions were found to dissociate over the same minimum energy reaction pathway, the only difference being the site of initial protonation. α-Pinene preferentially protonates at the bridging carbon, while β-pinene can only significantly protonate at the exocyclic double bond. This leads to a lower appearance energy for loss of isobutene, and thus relatively greater m/z 81 fragment ion abundance for β-pinene.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The distinct sites of initial protonation result in the subtle differences observed in the CID of α- and β-pinene. The work highlights that it is not necessarily the “lowest energy” ion that will be formed in the ion source, and any distribution of initial structures must be accounted for when examining CID mass spectra.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11684416/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142906391","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":"Combining the 15N Gas Flux Method and N2O Isotopocule Data for the Determination of Soil Microbial N2O Sources","authors":"Gianni Micucci,&nbsp;Dominika Lewicka-Szczebak,&nbsp;Fotis Sgouridis,&nbsp;Reinhard Well,&nbsp;Caroline Buchen-Tschiskale,&nbsp;Niall P. McNamara,&nbsp;Stefan Krause,&nbsp;Iseult Lynch,&nbsp;Felicity Roos,&nbsp;Sami Ullah","doi":"10.1002/rcm.9971","DOIUrl":"10.1002/rcm.9971","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The analysis of natural abundance isotopes in biogenic N₂O molecules provides valuable insights into the nature of their precursors and their role in biogeochemical cycles. However, current methodologies (for example, the isotopocule map approach) face limitations, as they only enable the estimation of combined contributions from multiple processes at once rather than discriminating individual sources. This study aimed to overcome this challenge by developing a novel methodology for the partitioning of N₂O sources in soil, combining natural abundance isotopes and the use of a ¹⁵N tracer (¹⁵N Gas Flux method) in parallel incubations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Laboratory incubations of an agricultural soil were conducted to optimize denitrification conditions through increased moisture and nitrate amendments, using nitrate that was either ¹⁵N-labeled or unlabeled. A new linear system combined with Monte Carlo simulation was developed to determine N₂O source contributions, and the subsequent results were compared with FRAME, a Bayesian statistical model for stable isotope analysis.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Our new methodology identified bacterial denitrification as the dominant process (87.6%), followed by fungal denitrification (9.4%), nitrification (1.5%), and nitrifier denitrification (1.6%). Comparisons with FRAME showed good agreement, although FRAME estimated slightly lower bacterial denitrification (80%) and higher nitrifier-denitrification (9%) contributions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This approach provides an improved framework for accurately partitioning N₂O sources, enhancing understanding of nitrogen cycling in agroecosystems, and supporting broader environmental applications.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11671725/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142890763","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}