Journal of Mass Spectrometry最新文献

{"title":"Comparison of Mid-Infrared and Ultraviolet Lasers Coupled to the MALDESI Source for the Detection of Secondary Metabolites and Structural Lipids in Arabidopsis thaliana","authors":"Sarah M. Ashbacher,&nbsp;Jeffrey G. Manni,&nbsp;David C. Muddiman","doi":"10.1002/jms.5118","DOIUrl":"https://doi.org/10.1002/jms.5118","url":null,"abstract":"<p>Matrix-assisted laser desorption electrospray ionization (MALDESI) conventionally utilizes a mid-infrared (IR) laser for the desorption of neutrals, allowing for detection of hundreds to thousands of analytes simultaneously. This platform enables mass spectrometry imaging (MSI) capabilities to not only detect specific molecules but also reveal the distribution and localization of a wide range of biomolecules across an organism. However, an IR laser comes with its disadvantages when imaging plants. At a mid-IR wavelength (2970 nm), the compartmentalized endogenous water within the leaf structure acts as an internal matrix, causing rapid heating, and, in turn, degrades the spatial resolution and signal quality. An ultraviolet (UV) laser operates at wavelengths that overlap with the absorption bands of secondary metabolites allowing them to serve as sacrificial matrix molecules. With the integration and optimization of a 355 nm UV laser into the MALDESI-MSI NextGen source for the analysis of plants, we were able to detect diverse molecular classes including flavonoids, fatty acid derivatives, galactolipids, and glucosinolates, at higher ion abundances when compared to the mid-IR laser. These results show that re-visiting UV-MALDESI-MSI, without the need for an exogenous matrix, provides a promising approach for the detection and imaging of important analytes in plants.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jms.5118","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431584","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":"Minimizing Variable Downhole Fractionation in U–Pb Zircon Geochronology by LA-MC-ICP-MS at Smaller Spot Size","authors":"Saurabh Singhal,&nbsp;Sandeep Singh,&nbsp;Dharmendra Singh","doi":"10.1002/jms.5115","DOIUrl":"https://doi.org/10.1002/jms.5115","url":null,"abstract":"<div>\u0000 \u0000 <p>The development of LA-ICPMS and LA-MC-ICPMS resulted in analytical methods for zircon geochronology using a 20- to 60-μm laser spot size. A high amount of complexly zoned zircons promotes the requirement of U–Pb dating at smaller spot sizes. When spot size reduces, downhole fractionation (DHF) increases, increasing the DHF discrepancy between zircon grains and the primary reference zircon standard and resulting in inaccurate results. With MC-ICPMS's high sensitivity and multi-collector capabilities, this work attempts to accurately determine age with spatial resolutions below 20 μm. Three well-characterized zircon standards (91500, GJ-1, and Plešovice) were tested at spot sizes of 35, 20, 15, and 10 μm. Laser and mass spectrometry tuning, laser shot count, and ablation time have been optimized to reduce the DHF effect on measurement accuracy. Static ablation of 35- to 15-μm spots with 150 laser shot counts (30 s) yielded precision of less than 1.5% and age offset of less than 2%. The DHF differs significantly from the reference standard and two test zircon samples used for validation, with an age offset of 4% at 10-μm spot sizes. Masking shot counts from the end enhanced accuracy, notably for lower laser shot counts and shorter ablation times. At 75 laser shot counts, precision reached 1.4% and age offsets reduced to 1.6% for ²⁰⁶Pb/²³⁸U age. This method minimizes laser shot counts to avoid sampling two age groups. Higher zircon DHF variability at smaller spot sizes may influence a well-calibrated, sensitive LA-MC-ICP-MS analytical figure of merit.</p>\u0000 </div>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143439092","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":"Mechanistic Insights Into the Dissociative Photoionization Pathways of Ethyl Propionate: A Combined Experimental and Theoretical Approach","authors":"Huanhuan Wang,&nbsp;Xiaobin Shan,&nbsp;Fuyi Liu,&nbsp;Zhenya Wang,&nbsp;Liusi Sheng,&nbsp;Ran Sui","doi":"10.1002/jms.5119","DOIUrl":"https://doi.org/10.1002/jms.5119","url":null,"abstract":"<div>\u0000 \u0000 <p>Ethyl propionate (C₅H₁₀O₂, EP) has been extensively studied in the fields of biofuels and atmospheric chemistry. However, its vacuum ultraviolet (VUV) photoionization has not been investigated. This study examines the photoionization process of EP using tunable VUV synchrotron radiation, coupled with a reflectron time-of-flight mass spectrometer. This method yielded the photoionization mass spectrum of EP and photoionization efficiency (PIE) spectra of 10 identified fragment ions (i.e., C₄H₇O₂^+., C₃H₇O₂^+., C₃H₆O₂^+., C₃H₅O₂^+., C₃H₆O^+., C₃H₅O^+., C₃H₄O^+., C₂H₅O^+., C₂H₅^+., and C₂H₄^+.). The results, interpreted with the aid of high-accuracy theoretical calculations, conclude possible formation mechanisms for each fragment ion. In the dissociation pathway of EP's cation, intramolecular hydrogen shifts and bond cleavage are the predominant processes. The C₃H₇O₂^+. and C₂H₄^+. reaction channels do not arise from one-step bond cleavage, but their reaction energy barriers are influenced by product energy, making them comparable to direct reaction channels. The active reaction sites within the molecules are elucidated using Laplacian bond order (LBO). Rate constants are calculated using RRKM theory, which confirms the kinetic factors governing the EP reaction process. This study provides a detailed understanding of the photoionization and dissociation of the main ions of EP within the 9.35–15.50 eV photon energy range.</p>\u0000 </div>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143423834","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":"Zn(II) Affinity and Structural Conformations of 2His-2Cys Zinc Finger-Like Motif Peptide Determined by Ion Mobility–Mass Spectrometry and PM6 Molecular Modeling","authors":"Richmond A. Adomako,&nbsp;Michael B. Owusu,&nbsp;Rebekah K. Oberdick,&nbsp;Kwabena Senyah,&nbsp;Perfect Asare,&nbsp;Riccardo Spezia,&nbsp;Laurence A. Angel","doi":"10.1002/jms.5113","DOIUrl":"10.1002/jms.5113","url":null,"abstract":"<div>\u0000 \u0000 <p>This study focuses on investigating the conformational structure and zinc(II) affinity of a zinc finger-like motif (ZFM) peptide with the sequence acetyl-<b>His</b>_<b>1</b><b>-Cys</b>_<b>2</b>-Gly₃-Pro₄-Gly₅-<b>His</b>_<b>6</b><b>-Cys</b>_<b>7</b>, where bold highlights the potential zinc(II) binding sites. Zinc fingers are crucial protein motifs known for their high specificity and affinity for zinc ions. The ZFM peptide's sequence contains the 2His-2Cys zinc-binding sites similar to those in natural zinc finger proteins but without the hydrophobic core, making it a valuable model for studying zinc(II)–peptide interactions. Previous research on related peptides showed that collision cross sections and B3LYP modeling predicted that the His-2Cys-carboxyl terminus coordination of zinc(II) was more stable than the 2His-2Cys. Employing a comprehensive approach integrating ion mobility–mass spectrometry and theoretical modeling techniques, various zinc(II) binding modes of the ZFM have been thoroughly compared to ascertain their influence on the competitive threshold collision-induced dissociation method for measuring the relative gas-phase Zn(II) affinity of the ZFM peptide. The measured Zn(II) affinity of ZFM is greater than those measured recently for two peptides with similar primary structures, acetyl-<b>His</b>_<b>1</b><b>-Cys</b>_<b>2</b>-Gly₃-Pro₄-Gly₅-Gly₆-<b>Cys</b>_<b>7</b> and acetyl-<b>Asp</b>_<b>1</b>-<b>His</b>_<b>2</b>-Gly₃-Pro₄-Gly₅-Gly₆-<b>Cys</b>_<b>7</b>, indicating the preference for the His₁-Cys₂-His₆-Cys₇ side groups for coordinating zinc(II) over the His-2Cys-carboxyl terminus or Asp-His-Cys-carboxyl terminus in these related heptapeptides.</p>\u0000 </div>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143414332","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":"Erratum—Integrating DFT and CI-MS Techniques to Assess Benzophenone Derivatives in Food Packaging: Implications for Enhancing Food Quality and Safety","authors":"Manjeet Bhatia","doi":"10.1002/jms.5105","DOIUrl":"10.1002/jms.5105","url":null,"abstract":"<p>The corrected enthalpy (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>Δ</mi>\u0000 <mi>H</mi>\u0000 </mrow>\u0000 <annotation>$$ Delta mathrm{H} $$</annotation>\u0000 </semantics></math>) and free energy (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>Δ</mi>\u0000 <mi>G</mi>\u0000 </mrow>\u0000 <annotation>$$ Delta mathrm{G} $$</annotation>\u0000 </semantics></math>) values for reactions of benzophenone derivatives with various CI-MS reagent ions are presented in Table 1. The values for reactions with NO⁺ and O<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msubsup>\u0000 <mrow></mrow>\u0000 <mrow>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 <mrow>\u0000 <mo>+</mo>\u0000 </mrow>\u0000 </msubsup>\u0000 </mrow>\u0000 <annotation>$$ {}_2^{+} $$</annotation>\u0000 </semantics></math> have been adjusted, as they were previously overestimated in Table 2.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 2","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jms.5105","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143006514","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":"digitalMALDI: A Single-Particle–Based Mass Spectrometric Detection System for Biomolecules","authors":"Dapeng Chen,&nbsp;Wayne A. Bryden,&nbsp;Michael McLoughlin,&nbsp;Scott A. Ecelberger,&nbsp;Timothy J. Cornish,&nbsp;Lara P. Moore,&nbsp;Kyle M. Regan","doi":"10.1002/jms.5110","DOIUrl":"10.1002/jms.5110","url":null,"abstract":"<div>\u0000 \u0000 <p>The development of a real-time system for characterizing individual biomolecule-containing aerosol particles presents a transformative opportunity to monitor respiratory conditions, including infections and lung diseases. Existing molecular assay technologies, although effective, rely on costly reagents, are relatively slow, and face challenges in multiplexing, limiting their use for real-time applications. To overcome these challenges, we developed digitalMALDI, a laser-based mass spectrometry system designed for single-particle characterization. digitalMALDI operates as a near real-time platform that directly samples aerosols, bypassing the need for complex and time-consuming sample preparation. To demonstrate the feasibility of this approach, intact insulin protein was used as a representative target. Results showed that digitalMALDI is capable of detecting 1 pg of insulin protein in single aerosol particles, suggesting that the system has a broad application for disease diagnosis, environmental monitoring, and biosecurity management.</p>\u0000 </div>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 2","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143006511","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":"Feasibility of IR-MALDESI Mass Spectrometry Imaging of PFAS","authors":"Allen Martin,&nbsp;Alena N. Joignant,&nbsp;Matt Farrell,&nbsp;Antonio Planchart,&nbsp;David C. Muddiman","doi":"10.1002/jms.5112","DOIUrl":"10.1002/jms.5112","url":null,"abstract":"<div>\u0000 \u0000 <p>Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a class of emerging contaminants that have been in use industrially since the 1940s. Their long-term and extensive commercial use has led to their ubiquitous presence in the environment. The ability to measure the bioconcentration and distribution of PFAS in the tissue of aquatic organisms helps elucidate the persistence of PFAS as well as environmental impacts. Traditional analysis by LC–MS/MS can measure total PFAS concentrations within an organism but cannot provide comprehensive spatial information regarding PFAS concentrations within the organism. In the current study, we used infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) to determine the limit of detection (LOD) of several PFAS utilizing a commercial standard mix spotted on mouse liver tissue. The traditional ice matrix and an alternative matrix, 1,8-bis (tetramethylguanidino)naphthalene (TMGN), were explored when determining the limits of detection for various PFAS by IR-MALDESI. The ice matrix alone resulted in a higher response than the combination of TMGN and ice. The resulting LOD for perfluorooctane sulfonic acid (PFOS) on a per voxel basis was 0.16 fmol/voxel. For comparison, zebrafish that were exposed to perfluorooctanoic acid (PFOA), PFOS, and perfluorohexanesulfonic acid (PFHxS) at different concentrations were homogenized, and PFAS were extracted by solid–liquid extraction, purified by solid phase extraction, and analyzed by LC–MS/MS to determine the level of bioaccumulation in the zebrafish. PFOS resulted in the highest level of bioaccumulation (731.9 μg/kg, or 234.2 fg/voxel). A zebrafish that had been exposed to a PFAS mixture of PFOA (250 ng/L), PFOS (250 ng/L), and PFHxS (125 ng/L) was cryosectioned and analyzed by IR-MALDESI. Images could not be generated as the accumulation of PFAS in the sectioned tissue was below detection limit of the technique.</p>\u0000 </div>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 2","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142978896","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":"Application of Online Multi-Internal Standard Calibration for Determination of Iodine by ICP-MS","authors":"Long-Hua Zhou,&nbsp;Xing-Chen Lin,&nbsp;Li-Li Suo,&nbsp;Li-Fang Ma,&nbsp;Gui-Xiang Hu,&nbsp;Xiang Xia,&nbsp;Ming Li,&nbsp;Wei-Hua Huang,&nbsp;Yong-Jiu Jin","doi":"10.1002/jms.5109","DOIUrl":"10.1002/jms.5109","url":null,"abstract":"<div>\u0000 \u0000 <p>This study presents a comprehensive evaluation of the application of online multi-internal standard calibration (M.ISC) in determining iodine concentrations through inductively coupled plasma mass spectrometry (ICP-MS). Notably, M.ISC streamlines the calibration process by requiring only a single standard solution, thereby enhancing sample throughput and minimizing liquid waste. In addition, unlike conventional internal standard (IS) methods, M.ISC omits the need for time-consuming species identification by utilizing multiple IS species simultaneously to minimize signal biases. The effectiveness of M.ISC was validated through the analysis of six standard reference samples, with the results of LOD and LOQ also being calculated by the error propagation approach. The traditional chemical analytical methods (TCAM), external standard calibration (EC) and single IS methods were also evaluated as comparative purpose. Nonetheless, M.ISC emerges as a straightforward matrix-correction strategy, offering a simple and efficient alternative to traditional calibration methods for iodine detection by ICP-MS.</p>\u0000 </div>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142931998","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":"Sodiation of Enhanced Green Fluorescent Protein (EGFP) in Basic Solution Studied by Electrospray Mass Spectrometry","authors":"Kenzo Hiraoka,&nbsp;Satoshi Ninomiya,&nbsp;Stephanie Rankin-Turner,&nbsp;Noa Suzuki,&nbsp;Satoko Akashi","doi":"10.1002/jms.5111","DOIUrl":"10.1002/jms.5111","url":null,"abstract":"<div>\u0000 \u0000 <p>In our previous work, the sodiation of melittin, cytochrome <i>c</i>, and ubiquitin in a 1 mM NaOH water/methanol solution was studied by electrospray mass spectrometry. It was suggested that the α-helix is more resistant to sodiation than the β-sheet. In this study, sodiation of enhanced green fluorescent protein (EGFP) composed of a β-barrel was studied in 1% CH₃COOH (AcOH) or 1 mM NaOH water/methanol solution by electrospray mass spectrometry. Although EGFP was denatured in an acidic solution, it maintains a near-native structure in a basic solution. For the 1% AcOH solution, the protonated EGFP, [EGFP + nH − mH + mNa]ⁿ⁺, with <i>n</i> = 14 − 36 and <i>m</i> = 0 was detected. For 1 mM NaOH, the number <i>n</i> for [EGFP + nH − mH + mNa]ⁿ⁺ was found to increase with the sodiation number <i>m</i> and vice versa for [EGFP + nH − mH + mNa]ⁿ⁻. Namely, Na⁺ adducts counteract the negative charges of deprotonated acidic residues. The protonated EGFP detected as major ions for basic 1 mM NaOH was ascribed to the more surface-active H₃O⁺(aq) than OH⁻(aq).</p>\u0000 </div>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142932002","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":"Cryogenic TOF-SIMS Around Sublimation Temperature of Quench-Condensed Noble Gas (Ne, Ar, and Kr) Films","authors":"Taku T. Suzuki","doi":"10.1002/jms.5107","DOIUrl":"10.1002/jms.5107","url":null,"abstract":"<div>\u0000 \u0000 <p>A possible TOF-SIMS analysis of surface phase transitions has recently been proposed for limited cases such as polymers and ionic liquids. In the present study, we have extended this analysis to quench-condensed noble gas films. The newly developed cryogenic TOF-SIMS allowed both measurements of TOF-SIMS below 4 K, and low-energy ion scattering spectroscopy that is used to prepare a clean surface. It was found that the TOF-SIMS intensity variation by increasing the temperature at a constant ramp rate (temperature-programmed TOF-SIMS) shows steep changes due to sublimation. Thus, the possibility of analyzing the surface phase transition at the local region defined by the incident ion beam of (cryogenic) TOF-SIMS was demonstrated in the present study.</p>\u0000 </div>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142877071","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}