International Journal of Mass Spectrometry最新文献

{"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}

{"title":"Environmental photosensitizers can exhibit enhanced actinic absorption in microhydrated clusters compared to solution","authors":"Nabiha Hasan ,&nbsp;Morgan Davies ,&nbsp;Mi’Kayla Word ,&nbsp;Zifan Ma ,&nbsp;Ahren W. Jasper ,&nbsp;Joseph A. Fournier ,&nbsp;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⁺∙(H₂O)_0-1, 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⁺∙(H₂O)_0-2, 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^‒, representing photosensitizers in basic conditions, quantum chemistry calculations predict that the UV–Vis spectra are ∼3x weaker in intensity than the brightest 4-BBAH⁺∙(H₂O)_0-1 features and were not observed experimentally. Quantum chemistry calculations predict one dominant UV–Vis feature is present in the spectra of 4-BBA^‒∙(H₂O)_0-2, 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}

{"title":"Stepwise optimization of traveling wave profiles and inverse gating pattern in structure for lossless ion manipulation platform","authors":"Latif Mohsen ,&nbsp;Xi Chen ,&nbsp;Gandhi Viraj ,&nbsp;Hua Leyan ,&nbsp;Brian Clowers ,&nbsp;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}

{"title":"Spatial mapping of phosphatidylcholine sn-positional isomers using CID of divalent metal complexes in imaging mass spectrometry","authors":"Tingting Yan ,&nbsp;Zunaira Naeem ,&nbsp;Zhongling Liang ,&nbsp;Hassan Azari ,&nbsp;Brent A. Reynolds ,&nbsp;Boone M. Prentice","doi":"10.1016/j.ijms.2024.117370","DOIUrl":"10.1016/j.ijms.2024.117370","url":null,"abstract":"<div><div>Phosphatidylcholines (PCs) are the main components of cellular membranes. The high degree of structural heterogeneity leads to significant variations in PC functions and complicates structural characterization. For example, the complex mixtures of lipid structures create challenges when analyzing and identifying these compounds directly from tissue in matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry experiments. Phosphatidylcholine (PCs) are preferentially ionized in the positive ion mode in MALDI imaging mass spectrometry. However, low-energy collision induced dissociation (CID) of protonated PCs largely only results in cleavages of the phosphocholine headgroup, with little to no information obtained about the fatty acyl chain identities and positions. Alternatively, metal cationization of lipids is known to generate increased structural information upon CID, but metal coordination has been less studied. Herein, we highlight the use of divalent metal-ligand complexes to produce new ion types for CID analysis in MALDI imaging mass spectrometry. CID of the new [PC + M + ligand]⁺ ion type (where M is a divalent metal) eliminates the headgroup loss fragmentation channel and opens new fragmentation channels at the fatty acyl chain positions. The gas-phase fragmentation behavior of [PC + M + ligand]⁺ ion type is characterized using multiple divalent metals and ligands. The fatty acyl chain product ions are then used to relatively quantify <em>sn</em>-positional isomers. Furthermore, this method is integrated into an imaging mass spectrometry workflow to enable the spatial mapping of PC <em>sn-</em>positional isomers in rat brain and glioblastoma tissues, revealing differential distributions of the <em>sn</em>-positional isomers.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"508 ","pages":"Article 117370"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143135479","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":"Relativistic effects in the gas-phase molecular hydration of heavy atomic transition metal cations (Groups 10–12): Group variations in energetics and kinetics","authors":"Voislav Blagojevic ,&nbsp;Diethard K. Böhme","doi":"10.1016/j.ijms.2024.117371","DOIUrl":"10.1016/j.ijms.2024.117371","url":null,"abstract":"<div><div>We assess relativistic effects in the molecular hydration of late atomic transition metal cations (Groups 10–12) as revealed by a review of previously published experimental and theoretical hydration energies and by kinetic measurements at room temperature. To fill gaps in theoretical hydration energies, we report here newly computed hydration energies, with and without relativistic effects, for all 9 atomic transition metal ions in the three Groups using DFT and RI-MP2 theory. Rate coefficients are taken from previous work in our laboratory and we provide here, for the first time, the raw experimental data for the kinetics of all 9 hydration reactions. Trends in hydration energies and hydration kinetics are inspected and compared going down the Periodic Table. We find a strong 3rd-row enhancements in the hydration energy and the rate of hydration and these are attributed to relativistic contributions to the bonding of H₂O to the 3rd-row transition metal cations. This behaviour is very much in line with that reported earlier with other molecular ligands.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"508 ","pages":"Article 117371"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143135480","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":"Infrared multiple photon dissociation spectroscopy of protonated amino acid clusters with non-interacting side chains in the gas phase","authors":"Jongcheol Seo ,&nbsp;Doui Kim ,&nbsp;Sandy Gewinner ,&nbsp;Wieland Schöllkopf ,&nbsp;Michael T. Bowers ,&nbsp;Kevin Pagel ,&nbsp;Gert von Helden","doi":"10.1016/j.ijms.2024.117394","DOIUrl":"10.1016/j.ijms.2024.117394","url":null,"abstract":"<div><div>We report on gas-phase aggregation and structural characteristics of protonated amino acid clusters investigated by ion mobility spectrometry-mass spectrometry (IMS-MS) and infrared multiple photon dissociation (IRMPD) spectroscopy. Amino acids, including valine, isoleucine, phenylalanine, tyrosine, and tryptophan, were studied to understand the formation and stabilization mechanisms of their clusters. The mass spectra reveal the formation of clusters, primarily as zwitterionic assemblies stabilized by extensive hydrogen-bond networks between protonated amine and deprotonated carboxylate groups. IRMPD spectra in the 1000–1900 cm⁻¹ region highlight distinctive vibrational features, indicating the presence of zwitterionic structures for clusters larger than octamers. Theoretical calculations support these findings, revealing a transition from non-zwitterionic to zwitterionic with increasing cluster size. Additionally, the charge state distribution analysis indicates that the cluster charge states correlate with their accessible surface area, supporting the applicability of the charged residue model (CRM) for their formation. These results offer valuable insights into the forces governing amino acid cluster assembly and highlight their potential as nanoscale models for studying biomolecular interactions.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"508 ","pages":"Article 117394"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143135566","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":"Rectification of kinematic parameters of dissociative ionization derived from ion momentum spectra","authors":"Akash Srivastav,&nbsp;Vishnu P,&nbsp;Bhas Bapat","doi":"10.1016/j.ijms.2024.117392","DOIUrl":"10.1016/j.ijms.2024.117392","url":null,"abstract":"<div><div>Ion momentum spectrometers, which are commonly used devices for studying molecular dissociation, are lossy devices in that not all charged fragments are assuredly detected. Combined with the fact that neutrals are always undetected, this can result in a mixing of distinct dissociation channels. A dissociation event with all charged fragments may mimic an event where at least one fragment is neutral. As a result, an analysis of the dissociation channels identified using an ion pair coincidence map may result in misleading interpretations, especially when analyzing channels with both charged and neutral fragments. In this study, we present a method to rectify the distributions of kinematic parameters for such cases. The rectification method is discussed in the context of the (O<span><math><msup><mrow></mrow><mrow><mo>+</mo></mrow></msup></math></span>, C<span><math><msup><mrow></mrow><mrow><mo>+</mo></mrow></msup></math></span>, O) breakup channel of the CO<span><math><msubsup><mrow></mrow><mrow><mn>2</mn></mrow><mrow><mn>2</mn><mo>+</mo></mrow></msubsup></math></span> molecular ion. The distribution of the kinematic parameters after rectification exhibit stark differences from the raw distributions, emphasizing the need for rectification. A comparison of the rectified data with cases in the literature where such losses are estimated to be negligible, underline the efficacy of the method.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"508 ","pages":"Article 117392"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143135567","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":"A boundary condition decoupled steady-state equivalent model for the simulation of FAIMS ion optical path","authors":"Jianhui Ji ,&nbsp;Shaomin Liu ,&nbsp;Han Wang ,&nbsp;Youjiang Liu ,&nbsp;Mengchao Jin ,&nbsp;Jie Sheng ,&nbsp;Shenglai Zhen ,&nbsp;Chilai Chen","doi":"10.1016/j.ijms.2024.117387","DOIUrl":"10.1016/j.ijms.2024.117387","url":null,"abstract":"<div><div>This paper proposed a boundary condition decoupled steady-state equivalent model (BCD-SSE Model) for high-field asymmetric waveform ion mobility spectrometry (FAIMS) ion optical path simulation, which successfully incorporated ion diffusion loss and oscillatory loss (dispersion voltage) into the steady-state simulation without altering the actual flow field distribution. The accuracy and efficiency of the model were verified by studying the effects of different dispersion voltage amplitudes, frequencies, duty cycles, and carrier gas flow rates on spectral peak characteristics (position, height, and width). The experimental results show that the spectrum generated by the BCD-SSE Model was in good agreement with the existing general FAIMS simulation model (SIMION/SDS Model). Additionally, the precision of the peak height and full width at half maximum (FWHM) in the FAIMS spectrum using the BCD-SSE Model is 10 times and 3 times greater than that of the traditional steady-state model (SS Model), respectively. Most importantly, compared to the SIMION/SDS Model, the BCD-SSE Model reduced the simulation time from the scale of hundreds of minutes to mere minutes, and it resolved the issue of instability in the simulation results encountered with the SIMION/SDS Model. The proposed method resolved the conflict between simulation accuracy and time consumption, provided a fast and accurate steady-state equivalent simulation method for the analysis of FAIMS ion transport processes and the optimization of ion optical path design.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"508 ","pages":"Article 117387"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143135478","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}