Journal of the American Society for Mass Spectrometry最新文献

{"title":"Headspace Injection Method for Intermittent Sampling and Profiling Analyses of Volatile Organic Compounds Using Dielectric Barrier Discharge Ionization (DBDI)","authors":"Daniel Heffernan,&nbsp;Frederik Oleinek,&nbsp;Ayla Schueler,&nbsp;Paak Wai Lau,&nbsp;Jürgen Kudermann,&nbsp;Alina Meindl,&nbsp;Mathias O. Senge and Nicole Strittmatter*,&nbsp;","doi":"10.1021/jasms.4c0047510.1021/jasms.4c00475","DOIUrl":"https://doi.org/10.1021/jasms.4c00475https://doi.org/10.1021/jasms.4c00475","url":null,"abstract":"<p >A direct headspace injection method is presented and optimized for the analysis of volatile organic compounds (VOCs) using dielectric barrier discharge ionization-mass spectrometry (DBDI-MS), incorporating an intermediate vial in which the sample headspace is injected. The setup is built of commonly available, cheap consumable parts and easily enables the incorporation of different gases for generating different ionization atmospheres. The method can be fully automated by using standard GC autosamplers, and its rapid analysis time is suitable for high-throughput applications. We show that this method is suitable for both profiling analysis of complex samples such as biofluids and quantitative measurements for real-time reaction monitoring. Our optimized method demonstrated improved reproducibility and sensitivity, with detection limits for compounds tested in the high nanomolar to the low micromolar range, depending on the compound. Key parameters for method optimization were identified such as sample vial volume, headspace-to-liquid ratio, incubation temperature, and equilibration time. These settings were systematically evaluated to maximize the signal intensity and improve repeatability between measurements. Two use cases are demonstrated: (i) quantitative measurement of ethanol production by a metal–organic framework from CO₂ and (ii) profiling of biofluids following the consumption of asparagus.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":"36 4","pages":"801–810 801–810"},"PeriodicalIF":3.1,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/jasms.4c00475","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143745887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanism of Copper Stress on Algae Determined Using Mass Spectrometry Molecular Network: Molecular Characteristics and Metabolite Identification","authors":"Yunkun Qian,&nbsp;Shuqi Wu,&nbsp;Yanan Liu,&nbsp;Yanan Chen,&nbsp;Jun Guo and Dong An*,&nbsp;","doi":"10.1021/jasms.4c0042610.1021/jasms.4c00426","DOIUrl":"https://doi.org/10.1021/jasms.4c00426https://doi.org/10.1021/jasms.4c00426","url":null,"abstract":"<p >Algae typically respond to environmental changes by regulating the production and release of metabolites that affect water quality and cause various environmental issues. In this study, we investigated the role of algal organic matter (AOM) in copper [Cu(II)] using high-resolution mass spectrometry and a molecular-network-based nontargeted screening. The abundance and activity of algae were inhibited after the addition of Cu(II). Lipids, proteins, lignins, condensed aromatic structures, CHO-only classes, and nitrogenous organic matter are the primary components of AOM. The addition of extracellular organic matter (EOM) and intracellular organic matter (IOM) promoted the generation of carbohydrates that bonded to Cu(II), thus weakening Cu(II) toxicity. Furthermore, 1006 and 589 unique formulas were observed in the Cu(II)-EOM and Cu(II)-IOM groups, respectively, illustrating that EOM and IOM can induce algae to produce different metabolites to resist Cu(II) stress. Six novel phosphatidylethanolamines (PEs) and three novel phosphatidylglycerols (PGs) were identified in the EOM of the Cu(II)-EOM group. Therefore, AOM addition enhanced the synthesis of novel low-unsaturation and palmitoylated PEs, thereby regulating the immune response of algal cells under Cu(II) stress. Overall, these results demonstrated that Cu(II) can perturb lipid utilization and storage, whereas algae can alleviate Cu(II) toxicity by synthesizing and secreting different lipids.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":"36 4","pages":"732–741 732–741"},"PeriodicalIF":3.1,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bromine-Based Derivatization of Carboxyl-Containing Metabolites for Liquid Chromatography–Trapped Ion Mobility Spectrometry–Mass Spectrometry","authors":"Kaylie I. Kirkwood-Donelson,&nbsp;Prashant Rai,&nbsp;Lalith Perera,&nbsp;Michael B. Fessler and Alan K. Jarmusch*,&nbsp;","doi":"10.1021/jasms.5c0002310.1021/jasms.5c00023","DOIUrl":"https://doi.org/10.1021/jasms.5c00023https://doi.org/10.1021/jasms.5c00023","url":null,"abstract":"<p >The analysis of small carboxyl-containing metabolites (CCMs), such as tricarboxylic acid (TCA) cycle intermediates, provides highly useful information about the metabolic state of cells. However, their detection using liquid chromatography–electrospray ionization–tandem mass spectrometry (LC-ESI-MS/MS) methods can face sensitivity and specificity challenges given their low ionization efficiency and the presence of isomers. Ion mobility spectrometry (IMS), such as trapped ion mobility spectrometry (TIMS), provides additional specificity, but further signal loss can occur during the mobility separation process. We, therefore, developed a solution to boost CCM ionization and chromatographic separation as well as leverage specificity of IMS. Inspired by carbodiimide-mediated coupling of carboxylic acids with 4-bromo-<i>N</i>-methylbenzylamine (4-BNMA) for quantitative analysis, we newly report the benefits of this reagent for TIMS-based measurement. We observed a pronounced (orders of magnitude) increase in signal and enhanced isomer separations, particularly by LC. We found that utilization of a brominated reagent, such as 4-BNMA, offered unique benefits for untargeted CCM measurement. Derivatized CCMs displayed shifted mobility out of the metabolite and lipid region of the TIMS-MS space as well as characteristic isotope patterns, which were leveraged for data mining with Mass Spectrometry Query Language (MassQL) and indication of the number of carboxyl groups. The utility of our LC-ESI-TIMS-MS/MS method with 4-BMA derivatization was demonstrated via the characterization of alterations in CCM expression in bone marrow-derived macrophages upon activation with lipopolysaccharide. While metabolic reprogramming in activated macrophages has been characterized previously, especially with respect to TCA cycle intermediates, we report a novel finding that isomeric itaconic, mesaconic, and citraconic acid increase after 24 h, indicating possible roles in the inflammatory response.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":"36 4","pages":"888–899 888–899"},"PeriodicalIF":3.1,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Static Limit in MeV Secondary Ion Mass Spectrometry","authors":"Mirjana Sepahyar Lorentzen,&nbsp;Boštjan Jenčič*,&nbsp;Primož Vavpetič and Primož Pelicon,&nbsp;","doi":"10.1021/jasms.5c0002410.1021/jasms.5c00024","DOIUrl":"https://doi.org/10.1021/jasms.5c00024https://doi.org/10.1021/jasms.5c00024","url":null,"abstract":"<p >Static limit in secondary ion mass spectrometry (SIMS) is defined as a threshold beam fluence, where secondary ions are desorbed only from the virgin surface. For the common SIMS technique, the static SIMS limit is set to approximately 10¹² ions/cm². Within the present paper, we investigated the applicability of the static limit for a mass spectrometry imaging technique known as MeV-SIMS, where the target surface is bombarded by primary ions within the MeV energy range domain. Here, desorption of secondary ions relies mainly on electronic excitations instead of collision cascades, as is the case for the lower energy primary ion beams. We have measured the disappearance cross sections of several organic targets for three different chlorine primary ion beam energies. Results show how the disappearance cross section depends on the primary ion beam energy. Generally, the static SIMS regime applies for a range of primary ion beam fluences similar to that for the common SIMS technique; however, the dependence of the disappearance cross section within the lower MeV energy domain (up to 10 MeV) exhibits somewhat unexpected characteristics. Further, we thoroughly investigated the dynamics of the secondary ion mass spectra after prolonged primary ion bombardment. Secondary ion yields of various peaks were monitored during analysis, and the corresponding data can be used to identify specific peaks and also to determine fragmentation patterns of analyzed organic molecules.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":"36 4","pages":"900–905 900–905"},"PeriodicalIF":3.1,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/jasms.5c00024","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pressure-Tunable Photoionization Tandem Ion Mobility Spectrometry for Investigating Proton Transfer Reactions of Binary Systems","authors":"Yiqian Xu,&nbsp;Qimu Yang,&nbsp;Yi Yu,&nbsp;Xuesong Zhang,&nbsp;Manman Pan,&nbsp;Dandan Jiang,&nbsp;Yuying Dong,&nbsp;Peng Gao,&nbsp;Lei Hua*,&nbsp;Chuang Chen* and Haiyang Li*,&nbsp;","doi":"10.1021/jasms.5c0005110.1021/jasms.5c00051","DOIUrl":"https://doi.org/10.1021/jasms.5c00051https://doi.org/10.1021/jasms.5c00051","url":null,"abstract":"<p >Investigating and manipulating the ion–molecule reactions within the ionization source of ion mobility spectrometry (IMS) or mass spectrometry can contribute to developing advanced ionization sources and novel analytical techniques. In this study, a pressure-tunable photoionization tandem ion mobility spectrometer (PI-tandem-IMS) was developed to investigate the ionization suppression caused by unusual proton transfer reactions in dual-analyte systems in which high proton affinity (PA) ions are deprotonated by low PA molecules. The proton transfer reaction mechanisms in the toluene–acetone and toluene–ethanol systems were studied. The experimental results showed the linear correlation between the ln(<i>S</i>_X2H⁺·<i>K</i>_0(T⁺₎/<i>S</i>_T⁺·<i>K</i>_0(X2H⁺₎ + 1) and the square of the reactant concentration <i>c</i>_X², as well as the cubic power of the pressure <i>p</i>³. Based on this, the generation of the proton-bound dimers in the toluene–acetone and toluene–ethanol systems was assigned as a termolecular process. The reaction rate coefficients <i>k</i> of the toluene–acetone and toluene–ethanol systems were calculated at different temperatures, and the Arrhenius plot showed that rate coefficients were both negatively correlated with temperature, implying that elevated temperatures suppress the proton transfer reaction. At 313.15 K, the calculated <i>k</i> values for the toluene–acetone and the toluene–ethanol systems were 2.2 × 10^–26 cm⁶/s and 5.2 × 10^–28 cm⁶/s, respectively, suggesting a higher inhibitory effect of acetone on toluene ionization than that of ethanol. Besides, the suppressive effect of reducing the pressure or increasing the reaction region electric field strength on proton transfer reactions was shown, which demonstrated the PI-tandem IMS was a good tool for understanding ion–molecule reactions in the ionization source.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":"36 4","pages":"914–922 914–922"},"PeriodicalIF":3.1,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Multipole Fields on the Performance and Dynamics of Quadrupole Linear Ion Traps","authors":"Fulong Deng,&nbsp;Xingliang He,&nbsp;Hongen Sun,&nbsp;Bin Wu,&nbsp;Yixiang Duan and Zhongjun Zhao*,&nbsp;","doi":"10.1021/jasms.4c0048810.1021/jasms.4c00488","DOIUrl":"https://doi.org/10.1021/jasms.4c00488https://doi.org/10.1021/jasms.4c00488","url":null,"abstract":"<p >Additional multipole fields are unavoidable in real quadrupole linear ion traps (QLITs) and play a crucial role in influencing their performance. In this study, the impact of these multipole fields on ion ejection and dynamics in QLITs is exhaustively analyzed using a vectorized Runge–Kutta method and a comprehensive theoretical model of ion vibration involving all the common multipole fields. The comparison of nonlinear resonance under different added multipole fields reveals obvious ion ejection from hexapole and octopole resonances as well as multiple resonance points in most multipole fields. Ion ejection with dipole excitation under these fields demonstrates distinct variations at different excitation working values, influenced by the inherent power distribution of ion motion in a linear quadrupole and the energy dispersion caused by the added multipole fields at varying stability parameters. Furthermore, theoretical and numerical analyses of ion dynamics mutually validate each other, offering the first comprehensive demonstration of ion excitation responses under various multipole fields across a wide stability range. The results show that for positive even-order multipole fields, forward scans lead to lower and more stable maximum amplitude responses compared to reverse scans, while the opposite is true for negative fields. In hexapole fields, the forward scan responses are lower than the reverse scan responses, and both increase sharply near nonlinear resonance points, regardless of field polarity. This work provides a thorough theoretical foundation for optimizing multipole field applications in QLITs.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":"36 4","pages":"811–822 811–822"},"PeriodicalIF":3.1,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computed Vibrational Heat Capacities for Gas-Phase Biomolecular Ions","authors":"Lawren R. Paris,&nbsp;Austin W. Green and James S. Prell*,&nbsp;","doi":"10.1021/jasms.5c0000810.1021/jasms.5c00008","DOIUrl":"https://doi.org/10.1021/jasms.5c00008https://doi.org/10.1021/jasms.5c00008","url":null,"abstract":"<p >Collision induced dissociation (CID) and collision induced unfolding (CIU) experiments are important tools for determining the structures of and differences between biomolecular complexes with mass spectrometry. However, quantitative comparison of CID/CIU data acquired on different platforms or even using different regions of the same instrument can be very challenging due to differences in gas identity and pressure, electric fields, and other experimental parameters. In principle, these can be reconciled by a detailed understanding of how ions heat, cool, and dissociate or unfold in time as a function of these parameters. Fundamental information needed to model these processes for different ion types and masses is their heat capacity as a function of the internal (<i>i.e.</i>, vibrational) temperature. Here, we use quantum computational theory to predict average heat capacities as a function of temperature for a variety of model biomolecule types from 100 to 3000 K. On a degree-of-freedom basis, these values are remarkably invariant within each biomolecule type and can be used to estimate heat capacities of much larger biomolecular ions. We also explore effects of ion heating, cooling, and internal energy distribution as a function of time using a home-built program (IonSPA). We observe that these internal energy distributions can be nearly Boltzmann for larger ions (greater than a few kDa) through most of the CID/CIU kinetic window after a brief (few-μs) induction period. These results should be useful in reconciling CID/CIU results across different instrument platforms and under different experimental conditions, as well as in designing instrumentation and experiments to control CID/CIU behavior.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":"36 4","pages":"862–872 862–872"},"PeriodicalIF":3.1,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Navigating the Postdoc Experience.","authors":"Chae Kyung Jeon, Daniel D Vallejo, Michael T Marty","doi":"10.1021/jasms.4c00448","DOIUrl":"10.1021/jasms.4c00448","url":null,"abstract":"<p><p>There are many reasons to consider postdoctoral research after completing a Ph.D. For those interested in academic careers at all levels, a postdoctoral research associate (PDRA) position is often required or at least preferred. Even for those interested in industry, government, or alternative careers, postdoctoral research provides opportunities to expand your knowledge and skill sets beyond your Ph.D. training. It can be a wonderful time to focus on research with minimal distractions and interruptions. However, there has been little discussion about the challenges of the postdoc transition. The postdoc experience can vary widely, but common challenges include transitioning into a new environment, learning new skills, serving in multiple roles as a mentor and mentee, different and sometimes unclear positions in the institution, and competition for limited opportunities. In this Commentary, we draw on our personal experiences and interviews with postdocs of various backgrounds and intersectionalities (gender, race, first-gen, neurodiversity, etc.) to discuss how to successfully navigate various aspects of the postdoc experience. Our perspective comes primarily within mass spectrometry (MS) research, but the interviews include several experiences outside of the MS field to develop discussions applicable to a broad range of PDRA experiences.</p>","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":" ","pages":"622-626"},"PeriodicalIF":3.1,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143456455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The 34th Sanibel Conference on Mass Spectrometry: Mass Spectrometry in Energy and the Environment","authors":"Amy M. McKenna,&nbsp; and ,&nbsp;Janne Jänis,&nbsp;","doi":"10.1021/jasms.5c0003510.1021/jasms.5c00035","DOIUrl":"https://doi.org/10.1021/jasms.5c00035https://doi.org/10.1021/jasms.5c00035","url":null,"abstract":"","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":"36 3","pages":"446–449 446–449"},"PeriodicalIF":3.1,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143547762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Remembrance: Dr. Jean H. Futrell.","authors":"Richard D Smith, David W Koppenaal","doi":"10.1021/jasms.4c00479","DOIUrl":"https://doi.org/10.1021/jasms.4c00479","url":null,"abstract":"","PeriodicalId":672,"journal":{"name":"Journal of the American Society for Mass Spectrometry","volume":"36 3","pages":"453-456"},"PeriodicalIF":3.1,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}