Amir Fayyaz , Muhammad Aslam Baig , Rizwan Ahmed , Muhammad Waqas
{"title":"Isotopic analysis of zinc plasma using Laser‒Ablation Time‒of‒Flight mass spectrometer","authors":"Amir Fayyaz , Muhammad Aslam Baig , Rizwan Ahmed , 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}
Kenzo Hiraoka , Stephanie Rankin-Turner , Dilshadbek T. Usmanov , Sherzod M. Akhmedov , Satoshi Ninomiya
{"title":"Leidenfrost phenomenon-assisted thermal desorption (LPTD) using a metal substrate coated with a fluoro compound: Mechanism of analyte evaporation","authors":"Kenzo Hiraoka , Stephanie Rankin-Turner , Dilshadbek T. Usmanov , Sherzod M. Akhmedov , 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}
Abigail M. Friese, Audrey R. Burrows, Scott L. Anderson
{"title":"High and ultra-high temperature reaction kinetics by single nanoparticle mass spectrometry","authors":"Abigail M. Friese, Audrey R. Burrows, 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 O<sub>2</sub> 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}
Erin L. Flannigan , William E. Kieser , Carley A. Crann , Christof Vockenhuber , Barbara B.A. Francisco
{"title":"3 MV accelerator mass spectrometry measurements of 36Cl using the Isobar Separator for Anions","authors":"Erin L. Flannigan , William E. Kieser , Carley A. Crann , Christof Vockenhuber , 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 <sup>36</sup>S via anion-gas reaction with NO<sub>2</sub> was evaluated for measurements of <sup>36</sup>Cl reference materials and a dilution series, using a 3 MV AMS system. The dilution series, with <sup>36</sup>Cl/Cl ratios ranging from 10<sup>−11</sup> to 10<sup>−15</sup>, were measured in comparison with external measurement. <sup>36</sup>Cl/Cl blank levels of (7 ± 4) x10<sup>−15</sup> were reached. While ISA-AMS is not currently able to achieve sufficient separation for most <sup>36</sup>Cl applications, these measurements show progress towards routine measurement of <sup>36</sup>Cl 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}
Julia Laskin, Zheng Ouyang, Isabelle Fournier, Stephen Blanksby
{"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, Zheng Ouyang, Isabelle Fournier, 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}
Sophia M. Wensman , Alyssa E. Shiel , Chris J. Russo , Adam J.R. Kent
{"title":"Evaluating use of laser ablation quadrupole inductively coupled plasma mass spectrometry for low concentration lead isotope measurements","authors":"Sophia M. Wensman , Alyssa E. Shiel , Chris J. Russo , 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<sup>−1</sup>) and environmental samples (i.e., Pacific oyster shells) with Pb concentrations below 1 μg g<sup>−1</sup>. Accuracy and precision were assessed using three glass reference materials (BCR-2G, BHVO-2G, and GOR128-G). For <sup>206</sup>Pb/<sup>207</sup>Pb and <sup>208</sup>Pb/<sup>207</sup>Pb 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 <sup>206</sup>Pb/<sup>207</sup>Pb and ∼1.3 % RSD for <sup>208</sup>Pb/<sup>207</sup>Pb) compared to oyster shells (∼3.6 % RSD for <sup>206</sup>Pb/<sup>207</sup>Pb and ∼3.8 % RSD for <sup>208</sup>Pb/<sup>207</sup>Pb), 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 (>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}
Clifton K. Fagerquist , Yanlin Shi , Mahesh Koirala
{"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 , Yanlin Shi , 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}
Nabiha Hasan , Morgan Davies , Mi’Kayla Word , Zifan Ma , Ahren W. Jasper , Joseph A. Fournier , Laura M. McCaslin
{"title":"Environmental photosensitizers can exhibit enhanced actinic absorption in microhydrated clusters compared to solution","authors":"Nabiha Hasan , Morgan Davies , Mi’Kayla Word , Zifan Ma , Ahren W. Jasper , Joseph A. Fournier , Laura M. McCaslin","doi":"10.1016/j.ijms.2025.117431","DOIUrl":"10.1016/j.ijms.2025.117431","url":null,"abstract":"<div><div>Brown carbon chromophores at environmental air-water interfaces often act as photosensitizers that absorb sunlight and subsequently transfer energy to nearby molecules, initiating a wide variety of chemical reactions. Despite their importance to understanding daytime chemistry at these air-water interfaces, little is known about the role of the solvation environment on the photophysical properties of these photosensitizers. In this work, we present a joint experimental-theoretical study of the vibrational and photophysical properties of microhydrated protonated and deprotonated 4-benzoylbenzoic acid (4-BBA), a key model system for environmental photosensitizers. We find that for protonated 4-BBAH<sup>+</sup>∙(H<sub>2</sub>O)<sub>0-1</sub>, representing photosensitizers in very acidic conditions, a single bright state dominates the UV–Vis spectrum between 280 and 400 nm. Comparing the experimental UV–Vis spectra and quantum chemistry-predicted spectra of 4-BBAH<sup>+</sup>∙(H<sub>2</sub>O)<sub>0-2</sub>, we find that the degree of microhydration has little effect on the UV–Vis spectra or the orbitals of the dominant feature. For deprotonated 4-BBA<sup>‒</sup>, representing photosensitizers in basic conditions, quantum chemistry calculations predict that the UV–Vis spectra are ∼3x weaker in intensity than the brightest 4-BBAH<sup>+</sup>∙(H<sub>2</sub>O)<sub>0-1</sub> features and were not observed experimentally. Quantum chemistry calculations predict one dominant UV–Vis feature is present in the spectra of 4-BBA<sup>‒</sup>∙(H<sub>2</sub>O)<sub>0-2</sub>, which exhibit minor shifts with degree of microhydration. While 4-BBA in bulk solution over a range of pH values has relatively weak absorption within the solar actinic region, we show that microhydrated 4-BBA has bright transitions within the actinic region. This indicates that the complex structure of environmental air-water interfaces can shift the absorption maximum of photosensitizers into the actinic region for enhanced absorption of sunlight and subsequent enhancement of photosensitizer-driven reactions.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"511 ","pages":"Article 117431"},"PeriodicalIF":1.6,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143520828","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":"Rapid and accurate identification of microorganisms using ion mobility–mass spectrometry","authors":"Ahmed M. Hamid","doi":"10.1016/j.ijms.2025.117421","DOIUrl":"10.1016/j.ijms.2025.117421","url":null,"abstract":"<div><div>Accurate identification of microorganisms to the strain and substrain levels in clinical and environmental samples is essential to provide an appropriate antibiotherapy to the patients and reduce the prescription of broad-spectrum antimicrobials to minimize antibiotic resistance. Unfortunately, the current diagnosis methods are often slow, expensive, or laborious, which limits their use in resource-limited regions. Therefore, there is a strong unmet need for new technologies that can rapidly identify microorganisms in complex samples to complement the existing commercially available technologies. This Young Scientist Perspective demonstrates the value of combining the attributes of ion mobility-mass spectrometry and ambient ionization, enabling rapid and accurate discrimination of bacteria to the species level after only a 4-h culturing period and showing that various bacterial species can have different isomers and conformers of their biomarkers. However, to discriminate closely-related bacterial strains, we needed to include other separation techniques in our workflow, such as liquid chromatography. Also, we utilized whole organism fingerprints, which include metabolites, lipids, and peptides, using our optimized workflow and machine learning to analyze a wide set of <em>E. coli</em> strains in artificially contaminated urine samples. Moreover, the various challenges for routine identification of microorganisms using our optimized techniques in medical, environmental, and security fields and future outlooks are discussed.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"510 ","pages":"Article 117421"},"PeriodicalIF":1.6,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437898","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}
Latif Mohsen , Xi Chen , Gandhi Viraj , Hua Leyan , Brian Clowers , Carlos Larriba-Andaluz
{"title":"Stepwise optimization of traveling wave profiles and inverse gating pattern in structure for lossless ion manipulation platform","authors":"Latif Mohsen , Xi Chen , Gandhi Viraj , Hua Leyan , Brian Clowers , Carlos Larriba-Andaluz","doi":"10.1016/j.ijms.2025.117420","DOIUrl":"10.1016/j.ijms.2025.117420","url":null,"abstract":"<div><div>The Structure for Lossless Ion Manipulation (SLIM) platform is a powerful analytical separation tool allowing ultra-long serpentine separation path spanning hundreds of meters. In SLIM, transient fields called Traveling waves (T-wave) roll over the ions leading to separation, hence a Stepwise optimization of experimental operating conditions including amplitude, speed, and shape is essential. Here, we have characterized seven T-wave profiles including sine, triangle, square, ramp, reverse ramp, and two decreasing fields as a function of obtained resolution, resolving power and signal intensities. We found out that T-wave patterns with the most uniform electric field and least negative electric fields produce the highest resolution (reverse ramp). Both signal intensity and resolution are favorable at mid-range T-wave amplitude and speeds. The inverse gating could potentially improve the obtained resolutions as much as 35 %, in the case of reverse ramp, within 1.5 m of separation path.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"510 ","pages":"Article 117420"},"PeriodicalIF":1.6,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403289","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}