International Journal of Mass Spectrometry最新文献

{"title":"Gas phase proton affinities of proline-containing peptides. 2: ProCys, ProMet, ProSer, ProThr, ProTyr, ProPhe, and ProTrp","authors":"Henry Cardwell ,&nbsp;Paul Acoria ,&nbsp;Alexis Brender A Brandis ,&nbsp;Kathy Huynh ,&nbsp;Madeleine Lamb ,&nbsp;Sophie Messinger ,&nbsp;Daria Moody ,&nbsp;Laurel Nicks ,&nbsp;Hao Qian ,&nbsp;Shantanu Rastogi ,&nbsp;Trinh Ton ,&nbsp;Anna Grace Towler ,&nbsp;Mark Valasquez ,&nbsp;Jennifer Poutsma ,&nbsp;John C. Poutsma","doi":"10.1016/j.ijms.2025.117445","DOIUrl":"10.1016/j.ijms.2025.117445","url":null,"abstract":"<div><div>The gas-phase proton affinities (PA) for a series of proline-containing dipeptides have been measured in an ESI triple quadrupole instrument using the extended kinetic method (EKM). Proton affinities of ProCys (<strong>1</strong>), ProMet (<strong>2</strong>), ProSer (<strong>3</strong>), ProThr (<strong>4</strong>), ProTyr (<strong>5</strong>), ProPhe (<strong>6</strong>), and ProTrp (<strong>7</strong>) were determined to be 966.9 ± 5.3, 987.9 ± 10.4, 978.4 ± 6.1, 978.3 ± 6.1, 993.9 ± 11.2, 985.1 ± 10.7, and 998.7 ± 7.6 kJ/mol, respectively. Predictions for the proton affinities for <strong>1</strong>–<strong>7</strong> were also obtained through isodesmic calculations at the B3LYP/6–311++G(d,p)//B3LYP/6-31+G(d) level of theory. As with a previous study on the proton affinities of ProXxx dipeptides with aliphatic side chains (Cardwell et al., <em>Int. J. Mass Spectrom.</em> <strong>2025</strong>, <em>507</em>, 117352) the agreement between theory and experiment is mixed. For the two dipeptides with sulfur in the side chain we find excellent agreement between the EKM and calculated proton affinities. For the three dipeptides with hydroxyl groups in the side chain, the experimental values are between 7.2 and 13.2 kJ/mol larger than the computed proton affinities. Additional single point energy calculations on <strong>3</strong>–<strong>5</strong> with B3LYP/6–311++G(2df,2p) basis sets give predicted proton affinities that are somewhat smaller than those predicted with the B3LYP/6–311++G9d,p) basis set. MP2/6-311z++G(2df,2p) single point energy calculations on <strong>3 and 4</strong> give calculated proton affinities within 1 kJ/mol of the B3LYP/6–311++G(d,p) values. It appears that the EKM values for <strong>3</strong>–<strong>5</strong> are systematically too high, possible o to the extrapolation required to obtain the isothermal point in the EKM workup due to the large protonation entropies of the dipeptides. This result is also seen to a lesser extent for ProPhe and ProTrp in which the EKM proton affinities are 5–6 kJ/mol larger than the calculated values. As with the aliphatic ProXxx dipeptides from our previous study, we recommend using the calculated proton affinities for <strong>1</strong>–<strong>7</strong> with the experimental proton affinities as upper limits.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"513 ","pages":"Article 117445"},"PeriodicalIF":1.6,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143852037","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":"Cyclic IMS-MS evidence for potential ring opening in collisionally activated sodiated cyclodextrins","authors":"Sudam S. Mane,&nbsp;Easton K. Cox,&nbsp;Cole D. Warner,&nbsp;David V. Dearden,&nbsp;Kenneth W. Lee","doi":"10.1016/j.ijms.2025.117444","DOIUrl":"10.1016/j.ijms.2025.117444","url":null,"abstract":"<div><div>Current tandem mass spectrometry-based methods for cyclodextrin characterization rely on exact mass and fragmentation patterns. Orthogonal methods are designed to provide additional information, increasing confidence in characterization. Ion mobility spectrometry (IMS) and mass spectrometry (MS) provide two dimensions where MS separates based on mass-to-charge and IMS separates based on size, shape, and charge. Here, we report new gas phase behavior of sodiated cyclodextrins revealed by cyclic IMS coupled to tandem MS. Gas phase ion activation prior to IMS separation on sodiated α-, β-, and γ-cyclodextrins generates isomeric species with different mobilities. Following gas phase mobility separation, fragmentation studies on the activation-generated isomers showed a greater degree of fragmentation than was observed for the original sodiated cyclodextrins. These findings suggest that sodiated cyclodextrins undergo structural changes upon activation, with the newly formed isomers significantly contributing to the observed fragmentation. To our knowledge this is the first report on separation of isomeric ions generated upon collisional activation of sodiated cyclodextrins in the gas phase. The results of this study can be used for better understanding of cyclodextrin fragmentation, suggesting that fragmentation occurs after an initial isomerization, possibly to a ring-opened form. Additionally, these findings can be used to develop more specific methodologies for cyclodextrin characterization.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"513 ","pages":"Article 117444"},"PeriodicalIF":1.6,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863381","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":"Amide bond formation between substances located in two immiscible liquid phases without phase-transfer catalyst","authors":"Xiao-Fei Gao ,&nbsp;Wei Xiao ,&nbsp;Meng Qiu ,&nbsp;Zhi-Gang Cheng ,&nbsp;Xiang-Zhao Chen","doi":"10.1016/j.ijms.2025.117443","DOIUrl":"10.1016/j.ijms.2025.117443","url":null,"abstract":"<div><div>Effectively amide bond construction between substances located in two immiscible liquids is a key point in the covalent-combination of the two parts with totally different characters. Herein, we demonstrated that aminolysis reactions between substances located in two immiscible solutions can be promoted in microdroplets without phase transfer catalyst, leading to amide bond formation products. Furthermore, in the biphasic reaction of microdroplets, size of the hydrophobic group and length of the alkyl chain in an activated ester may also affect a lot on the aminolysis reaction. This result will provide us a further insight on interfacial microdroplet reaction between substances located in two immiscible liquid phases and a new approach for ligation of two substances with totally different properties.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"512 ","pages":"Article 117443"},"PeriodicalIF":1.6,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143776880","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":"Isotopic analysis of zinc plasma using Laser‒Ablation Time‒of‒Flight mass spectrometer","authors":"Amir Fayyaz ,&nbsp;Muhammad Aslam Baig ,&nbsp;Rizwan Ahmed ,&nbsp;Muhammad Waqas","doi":"10.1016/j.ijms.2025.117442","DOIUrl":"10.1016/j.ijms.2025.117442","url":null,"abstract":"<div><div>In this study, we present the isotope analysis of zinc plasma using laser ablation time-of-flight mass spectrometry (LA-TOF-MS). The isotopes were detected based on their mass-to-charge (<em>m</em>/<em>z</em>) ratio. To improve the resolution of LA-TOF-MS, an aluminum disk with a 1 mm central opening was placed within a cylindrical magnetic filter (∼1 T) along the ion signal path. The electric field was applied using DC power, and the signal-to-noise ratio was monitored via an oscilloscope. Zinc isotopes; Zn-64, Zn-66, and Zn-68 were observed with high resolution within 1 μs by systematically applying electric fields in the ionization and extraction regions. The full-width half maximum (FWHM) significantly decreased with increasing electric field strength, from 0.215 to 0.137 μs for Zn-64, 0.294 to 0.146 μs for Zn-66, and 0.239 to 0.190 μs for Zn-68. The mass concentrations for Zn-64, Zn-66, and Zn-68 were estimated to be 48.6 %, 27.9 %, and 18.8 %, respectively, within ±0.1 % uncertainty, which is in agreement with the reported values in the literature. Laser-induced breakdown spectroscopy (LIBS) is used for plasma characterization and rapid qualitative identification of the constituent elements in the sample under study. Energy-dispersive X-ray (EDX) spectroscopy is applied for the cross-validation of the qualitative results obtained using LIBS. Since spectroscopically pure zinc was used in this study, spectral lines of any impurity elements may also appear in both spectra. However, LA-TOF-MS yields peaks along the arrival time scale of the constituent ions in the sample. The results demonstrate that LA-TOF-MS, combined with LIBS and EDX techniques, suggest a rapid method for elemental/isotope analysis.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"512 ","pages":"Article 117442"},"PeriodicalIF":1.6,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143739756","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":"Leidenfrost phenomenon-assisted thermal desorption (LPTD) using a metal substrate coated with a fluoro compound: Mechanism of analyte evaporation","authors":"Kenzo Hiraoka ,&nbsp;Stephanie Rankin-Turner ,&nbsp;Dilshadbek T. Usmanov ,&nbsp;Sherzod M. Akhmedov ,&nbsp;Satoshi Ninomiya","doi":"10.1016/j.ijms.2025.117434","DOIUrl":"10.1016/j.ijms.2025.117434","url":null,"abstract":"<div><div>In our previous work, direct analyses of low-volatility compounds have been performed using Leidenfrost phenomenon-assisted thermal desorption (LPTD). LPTD is affected by several factors such as substrate temperature, solvent properties, liquid volume, and surface-activity value of the analyte. In this work, the effects of surface properties of the metal substrate on LPTD were investigated by using a metal substrate with and without coating the surface with a fluoro compound. A 5 μL aliquot of 0.03 ppm of cocaine or morphine in methanol was dropped on the heater at 240 °C and mass spectra were measured as a function of time. The heater surface was polished with an abrasive agent with grit number of #5000 (alumina powder with ∼3 μm in diameter). When a non-coated metal was used for cocaine and morphine, analyte evaporation was observed only after the complete evaporation of methanol. However, when the metal surface was coated with a fluoro compound, evaporation of surface-active morphine accompanied by the rapid evaporation of methanol was observed. This is due to the rapid temperature rise of the droplet at the last moment of Leidenfrost phenomenon resulting in the occurrence of flash evaporation of morphine. This phenomenon was not observed for non-surface active cocaine.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"512 ","pages":"Article 117434"},"PeriodicalIF":1.6,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143681973","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 and ultra-high temperature reaction kinetics by single nanoparticle mass spectrometry","authors":"Abigail M. Friese,&nbsp;Audrey R. Burrows,&nbsp;Scott L. Anderson","doi":"10.1016/j.ijms.2025.117435","DOIUrl":"10.1016/j.ijms.2025.117435","url":null,"abstract":"<div><div>Methodology is presented for non-destructive, optically-detected single nanoparticle (NP) mass spectrometry, with the goal of extracting surface reaction kinetics for single NPs at high temperatures. Methods for determining the NP charge, mass, and temperature as a function of time are discussed, and the data are used to extract both the absolute kinetics for mass change, as well as the efficiencies of the surface processes that cause them. Factors that contribute to the uncertainties in absolute and relative mass determination, and in the resulting kinetic parameters, are discussed. The method allows the NP-to-NP variations in initial reactivity to be measured directly, along with the time evolution of reactivity resulting from NP structural/compositional changes that occur under reaction conditions.</div><div>The strengths and limitations of single nanoparticle mass spectrometry as a high temperature surface kinetics tool are discussed in the context of sublimation and O₂ oxidation kinetics experiments for single hafnium (Hf) NPs at temperatures ranging above 2400 K. The Hf oxidation kinetics are compared to analogous oxidation experiments for silicon, graphite, and carbon black NPs. In all four cases, the oxidation chemistry was dominated by processes that result in net mass loss, and the distinct mechanisms responsible are discussed. All four NPs also eventually passivated, i.e., the efficiencies for oxidative etching decreased by at least two orders of magnitude, relative to the initial efficiencies. The passivation mechanisms, which are quite different for carbon, compared to silicon or hafnium, are discussed. Carbon NP passivation is attributed to structural isomerization leading to fully coordinated, fullerene-like NP surfaces, while for silicon and hafnium, passivation results from delayed formation of an oxide layer, triggered by accumulation of oxygen in the NP sub-surface region.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"512 ","pages":"Article 117435"},"PeriodicalIF":1.6,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143681975","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":"3 MV accelerator mass spectrometry measurements of 36Cl using the Isobar Separator for Anions","authors":"Erin L. Flannigan ,&nbsp;William E. Kieser ,&nbsp;Carley A. Crann ,&nbsp;Christof Vockenhuber ,&nbsp;Barbara B.A. Francisco","doi":"10.1016/j.ijms.2025.117433","DOIUrl":"10.1016/j.ijms.2025.117433","url":null,"abstract":"<div><div>A second low-energy injection line containing the Isobar Separator for Anions (ISA), a radiofrequency quadrupole reaction cell system, was installed on the 3 MV tandem accelerator system at the A. E. Lalonde (AEL) accelerator mass spectrometry (AMS) Laboratory. The suppression of ³⁶S via anion-gas reaction with NO₂ was evaluated for measurements of ³⁶Cl reference materials and a dilution series, using a 3 MV AMS system. The dilution series, with ³⁶Cl/Cl ratios ranging from 10⁻¹¹ to 10⁻¹⁵, were measured in comparison with external measurement. ³⁶Cl/Cl blank levels of (7 ± 4) x10⁻¹⁵ were reached. While ISA-AMS is not currently able to achieve sufficient separation for most ³⁶Cl applications, these measurements show progress towards routine measurement of ³⁶Cl and demonstrate the steps required to validate such measurements on lower energy AMS systems.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"511 ","pages":"Article 117433"},"PeriodicalIF":1.6,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642304","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":"The IJMS Young Scientist Feature: A special article collection featuring perspectives and critical insights from early career mass spectrometrists around the globe","authors":"Julia Laskin,&nbsp;Zheng Ouyang,&nbsp;Isabelle Fournier,&nbsp;Stephen Blanksby","doi":"10.1016/j.ijms.2025.117432","DOIUrl":"10.1016/j.ijms.2025.117432","url":null,"abstract":"","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"512 ","pages":"Article 117432"},"PeriodicalIF":1.6,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143706231","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":"Evaluating use of laser ablation quadrupole inductively coupled plasma mass spectrometry for low concentration lead isotope measurements","authors":"Sophia M. Wensman ,&nbsp;Alyssa E. Shiel ,&nbsp;Chris J. Russo ,&nbsp;Adam J.R. Kent","doi":"10.1016/j.ijms.2025.117429","DOIUrl":"10.1016/j.ijms.2025.117429","url":null,"abstract":"<div><div>Lead (Pb) concentrations and isotopic compositions in environmental samples can provide important insights into Pb sources, pathways, and distributions. However, low Pb levels in many environmental samples present challenges for precise Pb isotopic measurements. This study evaluates the use of laser ablation quadrupole inductively coupled plasma mass spectrometry (LA-Q-ICP-MS) combined with collisional focusing and an Aerosol Rapid Introduction System (ARIS) for measuring Pb isotopes in reference materials with variable Pb concentrations (0.3–11 μg g⁻¹) and environmental samples (i.e., Pacific oyster shells) with Pb concentrations below 1 μg g⁻¹. Accuracy and precision were assessed using three glass reference materials (BCR-2G, BHVO-2G, and GOR128-G). For ²⁰⁶Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁷Pb ratios, measurements were within 0.2 % and 2.8 % of reported values for all reference materials, with decreased accuracy associated with low count rates. The precision was 0.4%–1.8 % relative standard deviation (RSD) for certified reference materials. Analytical uncertainty was lower for reference materials (∼1.2 % RSD for ²⁰⁶Pb/²⁰⁷Pb and ∼1.3 % RSD for ²⁰⁸Pb/²⁰⁷Pb) compared to oyster shells (∼3.6 % RSD for ²⁰⁶Pb/²⁰⁷Pb and ∼3.8 % RSD for ²⁰⁸Pb/²⁰⁷Pb), likely due to low Pb concentrations and sample heterogeneity. While Pb isotopic measurements demonstrated good repeatability across parallel transects of the same oyster shell (r = 0.7), the higher analytical uncertainties (&gt;0.5 % RSD) limit reliable source identification or apportionment in these natural samples. In approaching new studies with the methods presented here, researchers will need to determine if for a given application the uncertainties on measured sample Pb isotope ratios are sufficiently small.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"511 ","pages":"Article 117429"},"PeriodicalIF":1.6,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521266","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":"Plasmid-encoded gene expression of pathogenic bacteria by antibiotic induction as detected by MALDI-TOF-TOF mass spectrometry and top-down proteomic analysis","authors":"Clifton K. Fagerquist ,&nbsp;Yanlin Shi ,&nbsp;Mahesh Koirala","doi":"10.1016/j.ijms.2025.117430","DOIUrl":"10.1016/j.ijms.2025.117430","url":null,"abstract":"<div><div>Three previously genomically sequenced Shiga toxin-producing <em>E. coli</em> (STEC) strains of serotypes O43:H2, O103:H11, O111:H8 were analyzed by antibiotic induction, MALDI-TOF-TOF mass spectrometry and top-down proteomic analysis. In addition to detection and identification of phage-encoded Shiga toxin, we identified plasmid-encoded immunity proteins for colicin E8 and colicin D. Protein biomarkers were identified from b- and y-type fragment ions generated by the <em>aspartic acid effect</em> (AAE) that favors backbone cleavage on the C-terminal side of aspartic acid (D), glutamic acid (E) and asparagine (N) residues. Our in-house software was used for protein biomarker identification. Consistent with our previous report, we observed an apparent enhancement of the AAE when the residue on the C-terminal side of D-, E− or N-residues is a glycine (G). <em>In silico</em> predicted protein structures revealed that these DG, EG, NG sites of backbone breakage often correspond to flexible linker regions of the backbone. Finally, each pathogenic strain carried one or more large plasmids as well as a 6–8 kb plasmid that contained the colicin gene and its cognate immunity gene. Immediately upstream of the colicin gene was an SOS/LexA box to which the repressor protein (LexA) binds and blocks expression of genes downstream. Upon initiation of the SOS response by antibiotic induction, LexA undergoes self-cleavage and detachment allowing downstream gene expression. Thus, the presence of these small plasmids, their genes and the mechanism of expression is consistent with antibiotic induction and top-down proteomic analysis.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"511 ","pages":"Article 117430"},"PeriodicalIF":1.6,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526898","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}