Pub Date : 2026-01-15DOI: 10.1016/j.ijms.2026.117584
Zixuan Huang, Ran Tian, Yun Gao
Lithium-ion batteries (LIBs) are pivotal in advancing electronic technology and sustainable energy systems. However, characterizing lithium, the central element in LIBs, remains challenging due to its low atomic mass, which limits its detection by conventional techniques like energy-dispersive X-ray spectroscopy (EDS). Time-of-flight secondary ion mass spectrometry (TOF-SIMS) emerges as a powerful solution, leveraging its high surface sensitivity and capability to detect all elements, including lithium. This review outlines the fundamental principles of TOF-SIMS and highlights its pivotal applications in analyzing LIB components, including anodes, cathodes, and solid-state electrolytes.We critically assess specific testing methodologies and operational modes, providing a clear perspective on how TOF-SIMS elucidates interfacial phenomena and component distribution. Finally, we offer an outlook on the future utilization of TOF-SIMS to deepen the understanding of electrochemical mechanisms in LIBs. This review aims to establish a new pathway for lithium characterization, thereby accelerating the development of high-performance LIBs.
{"title":"The review of time of flight secondary ion mass spectrometry technology in LIBs","authors":"Zixuan Huang, Ran Tian, Yun Gao","doi":"10.1016/j.ijms.2026.117584","DOIUrl":"10.1016/j.ijms.2026.117584","url":null,"abstract":"<div><div>Lithium-ion batteries (LIBs) are pivotal in advancing electronic technology and sustainable energy systems. However, characterizing lithium, the central element in LIBs, remains challenging due to its low atomic mass, which limits its detection by conventional techniques like energy-dispersive X-ray spectroscopy (EDS). Time-of-flight secondary ion mass spectrometry (TOF-SIMS) emerges as a powerful solution, leveraging its high surface sensitivity and capability to detect all elements, including lithium. This review outlines the fundamental principles of TOF-SIMS and highlights its pivotal applications in analyzing LIB components, including anodes, cathodes, and solid-state electrolytes.We critically assess specific testing methodologies and operational modes, providing a clear perspective on how TOF-SIMS elucidates interfacial phenomena and component distribution. Finally, we offer an outlook on the future utilization of TOF-SIMS to deepen the understanding of electrochemical mechanisms in LIBs. This review aims to establish a new pathway for lithium characterization, thereby accelerating the development of high-performance LIBs.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"521 ","pages":"Article 117584"},"PeriodicalIF":1.7,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034255","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}
Micro(nano)plastics have received increased attention as environmental contaminants due to their harmful effects on ecosystems and human health. Conventional extraction methods for microplastic analysis are often lengthy and complicated, resulting in the loss of important chemical components such as additives. In this study, we provide a complementary approach, utilizing matrix-assisted laser desorption/ionization (MALDI) and direct analysis in real time (DART) mass spectrometry (MS) techniques, with minimal extraction and sample preparation to preserve both polymer and additive information. MALDI-MS was applied to aqueous samples collected along the shores of Lake Erie and the Cuyahoga River, successfully identifying the base polymer(s) in the micro(nano)plastics content of these samples, which included polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene (PE), and polymethylmethacrylate (PMMA). Simultaneously, DART-MS was used to analyze macroplastics debris collected from the same locations, enabling sensitive detection of the additives and plasticizers that are likely leaching into the aquatic environment. DART-MS macroplastics analysis additionally revealed the presence of PE and PEO chains in the plastic litter, corroborating the MALDI-MS data from the water samples and providing strong evidence for contaminant transfer from discarded plastics to the aquatic environment. Finally, DART-MS analysis of the water samples showed additives and plasticizers matching those present in the litter. This study combined both MALDI-MS and DART-MS analysis for the first time, offering a more comprehensive assessment of the base polymer composition and associated additives. By minimizing extraction steps, this approach improves the detection of compounds often lost by conventional methods, ultimately providing deeper insight into microplastic pollution and its toxicological implications.
{"title":"Identification of microplastics and additives from the Lake Erie watershed and the Cuyahoga River via MALDI-MS and DART-MS","authors":"Luciana Rivera Molina , Robert Brand , Calum Bochenek , Chrys Wesdemiotis","doi":"10.1016/j.ijms.2026.117581","DOIUrl":"10.1016/j.ijms.2026.117581","url":null,"abstract":"<div><div>Micro(nano)plastics have received increased attention as environmental contaminants due to their harmful effects on ecosystems and human health. Conventional extraction methods for microplastic analysis are often lengthy and complicated, resulting in the loss of important chemical components such as additives. In this study, we provide a complementary approach, utilizing matrix-assisted laser desorption/ionization (MALDI) and direct analysis in real time (DART) mass spectrometry (MS) techniques, with minimal extraction and sample preparation to preserve both polymer and additive information. MALDI-MS was applied to aqueous samples collected along the shores of Lake Erie and the Cuyahoga River, successfully identifying the base polymer(s) in the micro(nano)plastics content of these samples, which included polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene (PE), and polymethylmethacrylate (PMMA). Simultaneously, DART-MS was used to analyze macroplastics debris collected from the same locations, enabling sensitive detection of the additives and plasticizers that are likely leaching into the aquatic environment. DART-MS macroplastics analysis additionally revealed the presence of PE and PEO chains in the plastic litter, corroborating the MALDI-MS data from the water samples and providing strong evidence for contaminant transfer from discarded plastics to the aquatic environment. Finally, DART-MS analysis of the water samples showed additives and plasticizers matching those present in the litter. This study combined both MALDI-MS and DART-MS analysis for the first time, offering a more comprehensive assessment of the base polymer composition and associated additives. By minimizing extraction steps, this approach improves the detection of compounds often lost by conventional methods, ultimately providing deeper insight into microplastic pollution and its toxicological implications.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"521 ","pages":"Article 117581"},"PeriodicalIF":1.7,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973821","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}
Pub Date : 2026-01-09DOI: 10.1016/j.ijms.2026.117571
M. Azizi , B. Ghasemi , O. Kakuee , A. Biganeh
High-energy resolution alpha spectrometry is essential for accurate nuclear decay data. The Time-Of-Flight (TOF) technique offers high-resolution measurements of alpha particle energy, but several factors can impact spectral resolution, leading to spectral broadening. This study examines the primary sources of uncertainty in TOF alpha spectrometry, assessing the effect of each factor through computational and experimental methods. Results show that energy loss and straggling of alpha particles in the foil, as well as the transit time spread of secondary electrons to the electron detector, significantly affect spectrum broadening. Mitigating these effects through optimized carbon foils and transmission detector design can enhance resolution and measurement precision.
{"title":"Identification and analysis of resolution-limiting factors in an alpha time-of-flight spectrometer","authors":"M. Azizi , B. Ghasemi , O. Kakuee , A. Biganeh","doi":"10.1016/j.ijms.2026.117571","DOIUrl":"10.1016/j.ijms.2026.117571","url":null,"abstract":"<div><div>High-energy resolution alpha spectrometry is essential for accurate nuclear decay data. The Time-Of-Flight (TOF) technique offers high-resolution measurements of alpha particle energy, but several factors can impact spectral resolution, leading to spectral broadening. This study examines the primary sources of uncertainty in TOF alpha spectrometry, assessing the effect of each factor through computational and experimental methods. Results show that energy loss and straggling of alpha particles in the foil, as well as the transit time spread of secondary electrons to the electron detector, significantly affect spectrum broadening. Mitigating these effects through optimized carbon foils and transmission detector design can enhance resolution and measurement precision.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"521 ","pages":"Article 117571"},"PeriodicalIF":1.7,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940123","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}
Pub Date : 2026-01-08DOI: 10.1016/j.ijms.2026.117579
Zhe Fang , Lei Wang , Kai Li , Chaogang Wang , Lizhi Ren , Yaqiang Li , Yihui Wang , Ming Chen , Haizhou Wang
A membrane deposition–laser ablation sampling system was developed, in which the generated dry aerosol was introduced into an inductively coupled plasma mass spectrometer (ICP-MS). Based on this system, a micro-sampling method was established for the determination of gadolinium (Gd), dysprosium (Dy), and ytterbium (Yb) in high-purity cerium oxide. The gas composition in the ablation cell, carrier-gas flow rates, and laser spot sizes were systematically optimized. Carrier gas 1 was argon (Ar) at 1.0 L/min, and carrier gas 2 was helium (He) at 1.1 L/min. An optical aperture diameter of 2.75 mm was found to provide optimal performance. The membrane-deposition efficiency was evaluated from the ratio of the generated analyte mass to the mass determined post-deposition by ICP-MS/MS. Results showed that when the sampling volume was 100 μL and the cerium (Ce) matrix concentration exceeded 100 mg/L, the deposition efficiency approached 100 %. Internal-standard correction was applied to minimize fractionation and matrix effects, and the most suitable internal standards were identified. Under these optimized conditions, the detection limits for Gd, Dy, and Yb were 0.52, 0.18, and 0.21 ng/g, respectively. Analysis of three high-purity CeO2 samples showed that this method produced significantly lower Gd and Yb values than conventional ICP-MS, effectively eliminated hydroxide and oxide interferences, exhibited superior resistance to spectral interference, and provided results consistent with those from ICP-MS/MS.
{"title":"A membrane deposition - laser ablation - inductively coupled plasma mass spectrometry approach for the trace determination of dysprosium, gadolinium, and ytterbium in high-purity cerium oxide","authors":"Zhe Fang , Lei Wang , Kai Li , Chaogang Wang , Lizhi Ren , Yaqiang Li , Yihui Wang , Ming Chen , Haizhou Wang","doi":"10.1016/j.ijms.2026.117579","DOIUrl":"10.1016/j.ijms.2026.117579","url":null,"abstract":"<div><div>A membrane deposition–laser ablation sampling system was developed, in which the generated dry aerosol was introduced into an inductively coupled plasma mass spectrometer (ICP-MS). Based on this system, a micro-sampling method was established for the determination of gadolinium (Gd), dysprosium (Dy), and ytterbium (Yb) in high-purity cerium oxide. The gas composition in the ablation cell, carrier-gas flow rates, and laser spot sizes were systematically optimized. Carrier gas 1 was argon (Ar) at 1.0 L/min, and carrier gas 2 was helium (He) at 1.1 L/min. An optical aperture diameter of 2.75 mm was found to provide optimal performance. The membrane-deposition efficiency was evaluated from the ratio of the generated analyte mass to the mass determined post-deposition by ICP-MS/MS. Results showed that when the sampling volume was 100 μL and the cerium (Ce) matrix concentration exceeded 100 mg/L, the deposition efficiency approached 100 %. Internal-standard correction was applied to minimize fractionation and matrix effects, and the most suitable internal standards were identified. Under these optimized conditions, the detection limits for Gd, Dy, and Yb were 0.52, 0.18, and 0.21 ng/g, respectively. Analysis of three high-purity CeO<sub>2</sub> samples showed that this method produced significantly lower Gd and Yb values than conventional ICP-MS, effectively eliminated hydroxide and oxide interferences, exhibited superior resistance to spectral interference, and provided results consistent with those from ICP-MS/MS.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"522 ","pages":"Article 117579"},"PeriodicalIF":1.7,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146015852","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}
Pub Date : 2026-01-08DOI: 10.1016/j.ijms.2026.117578
Lasini Amunugama, Jared B. Shaw
Native top-down characterization of monoclonal antibodies (mAbs) is an attractive approach due to the narrow charge state distribution of the intact mAb and the spectral decongestion afforded by relatively low charge product ions being spread over a broad m/z range. However, low precursor charge and extensive disulfide bonding together greatly limit characterization by collision induced dissociation (CID). This study evaluates solution phase supercharging in ammonium acetate electrospray solutions to produce charge state distributions with intermediate charge, i.e., somewhere between native and fully denatured. Sequence coverage and interchain disulfide bond cleavage were evaluated as a function of precursor charge and collision energy for denatured, native, and supercharged “native” mAb precursor ions. Native ESI produced low charge precursors (z∼22–23) that required high collision energies (∼200–225 eV/q) for interchain disulfide cleavages (i.e., light chain (LC) release) and yielded modest sequence coverage. Formic acid, 50:50 acetonitrile/water with formic acid, dimethyl sulfoxide, propylene carbonate, and sulfolane were compared as additives; many increased precursors charge states but produced broader envelopes and degraded spectral quality. In contrast 3 % sulfolane in 100 mM ammonium acetate increased average charges to ∼39 for Infliximab and ∼42 for SigmaMAb and reduced the dissociation threshold to 125 eV/q as expected for higher charge precursor ions. Optimized conditions produced abundant [LC-S]/[LC]/[LC+S] triplets and extended b/y ions into CDR3 regions. Overall, adding 3 % sulfolane in ammonium acetate provides a practical way to overcome key CID limitations for intact mAbs and enables more extensive sequence characterization.
{"title":"Impact of supercharging on top-down characterization of monoclonal antibodies by collision induced dissociation","authors":"Lasini Amunugama, Jared B. Shaw","doi":"10.1016/j.ijms.2026.117578","DOIUrl":"10.1016/j.ijms.2026.117578","url":null,"abstract":"<div><div>Native top-down characterization of monoclonal antibodies (mAbs) is an attractive approach due to the narrow charge state distribution of the intact mAb and the spectral decongestion afforded by relatively low charge product ions being spread over a broad <em>m/z</em> range. However, low precursor charge and extensive disulfide bonding together greatly limit characterization by collision induced dissociation (CID). This study evaluates solution phase supercharging in ammonium acetate electrospray solutions to produce charge state distributions with intermediate charge, i.e., somewhere between native and fully denatured. Sequence coverage and interchain disulfide bond cleavage were evaluated as a function of precursor charge and collision energy for denatured, native, and supercharged “native” mAb precursor ions. Native ESI produced low charge precursors (z∼22–23) that required high collision energies (∼200–225 eV/q) for interchain disulfide cleavages (i.e., light chain (LC) release) and yielded modest sequence coverage. Formic acid, 50:50 acetonitrile/water with formic acid, dimethyl sulfoxide, propylene carbonate, and sulfolane were compared as additives; many increased precursors charge states but produced broader envelopes and degraded spectral quality. In contrast 3 % sulfolane in 100 mM ammonium acetate increased average charges to ∼39 for Infliximab and ∼42 for SigmaMAb and reduced the dissociation threshold to 125 eV/q as expected for higher charge precursor ions. Optimized conditions produced abundant [LC-S]/[LC]/[LC+S] triplets and extended b/y ions into CDR3 regions. Overall, adding 3 % sulfolane in ammonium acetate provides a practical way to overcome key CID limitations for intact mAbs and enables more extensive sequence characterization.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"521 ","pages":"Article 117578"},"PeriodicalIF":1.7,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973820","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}
Pub Date : 2026-01-03DOI: 10.1016/j.ijms.2026.117570
Erika A. Renbarger , Ian K. Webb
Cleavable crosslinking has traditionally been employed in bottom-up mass spectrometry to elucidate protein structure and protein-protein interactions through identification of peptides bearing characteristic mass adducts. Here, we demonstrate the application of cleavable crosslinking in top-down mass spectrometry to enhance fragmentation efficiency and enable precise localization of crosslink sites. We first validated this approach using cytochrome c, a well-characterized model protein. Subsequently, we extended top-down cleavable crosslinking to transthyretin, a natively homotetrameric protein exhibiting extensive proteoform heterogeneity, to investigate whether proteoform variations induce structural changes detectable by this method. Our results confirm that cleavable crosslinks can be detected and characterized by top-down mass spectrometry, with crosslinker cleavage under collisional activation significantly enhancing fragmentation. Application to transthyretin (intramolecular crosslinks) yielded complex crosslinking patterns that precluded complete identification of crosslinks. However, the crosslinking data provided valuable information on solvent-accessible residues, functioning effectively as a covalent labeling strategy. This work establishes cleavable crosslinking as a viable chemical crosslinking approach for top-down mass spectrometry applications.
{"title":"Evaluation of cleavable crosslinking for characterization of proteoform structural differences by top-down mass spectrometry","authors":"Erika A. Renbarger , Ian K. Webb","doi":"10.1016/j.ijms.2026.117570","DOIUrl":"10.1016/j.ijms.2026.117570","url":null,"abstract":"<div><div>Cleavable crosslinking has traditionally been employed in bottom-up mass spectrometry to elucidate protein structure and protein-protein interactions through identification of peptides bearing characteristic mass adducts. Here, we demonstrate the application of cleavable crosslinking in top-down mass spectrometry to enhance fragmentation efficiency and enable precise localization of crosslink sites. We first validated this approach using cytochrome <em>c, a</em> well-characterized model protein. Subsequently, we extended top-down cleavable crosslinking to transthyretin, a natively homotetrameric protein exhibiting extensive proteoform heterogeneity, to investigate whether proteoform variations induce structural changes detectable by this method. Our results confirm that cleavable crosslinks can be detected and characterized by top-down mass spectrometry, with crosslinker cleavage under collisional activation significantly enhancing fragmentation. Application to transthyretin (intramolecular crosslinks) yielded complex crosslinking patterns that precluded complete identification of crosslinks. However, the crosslinking data provided valuable information on solvent-accessible residues, functioning effectively as a covalent labeling strategy. This work establishes cleavable crosslinking as a viable chemical crosslinking approach for top-down mass spectrometry applications.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"521 ","pages":"Article 117570"},"PeriodicalIF":1.7,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940117","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}
Pub Date : 2025-12-29DOI: 10.1016/j.ijms.2025.117569
Yoichi Otsuka
Mass spectrometry imaging (MSI) is an essential technique for visualizing the distribution of molecules in biological tissues. Ambient sampling ionization-based MSI has attracted attention for its ability to analyze samples directly; however, improving spatial resolution remains a major technical challenge. Young Scientist developed a tapping-mode scanning probe electrospray ionization (t-SPESI) method that uniquely combines the core technologies of electrospray ionization (ESI) and atomic force microscopy (AFM). By using an oscillating capillary probe to periodically supply minute amounts of solvent to the sample surface, t-SPESI enables spatiotemporal separation of the extraction and ionization processes, allowing rapid, soft ionization of analytes in micro-regions of the sample. In addition, the oscillating probe senses the sample surface, minimizing the influence of surface topography on extraction and ionization during MSI. Young Scientist has further advanced high-spatial-resolution t-SPESI-MSI through the development of feedback-control methods, probe fabrication techniques, and miniaturization of t-SPESI units. This paper provides an overview of the progress made in the development of t-SPESI instrumentation and highlights MSI results obtained from tissues and single cells.
{"title":"Advances in tapping-mode scanning probe electrospray ionization (t-SPESI): Instrumental development for high-spatial-resolution ambient mass spectrometry imaging","authors":"Yoichi Otsuka","doi":"10.1016/j.ijms.2025.117569","DOIUrl":"10.1016/j.ijms.2025.117569","url":null,"abstract":"<div><div>Mass spectrometry imaging (MSI) is an essential technique for visualizing the distribution of molecules in biological tissues. Ambient sampling ionization-based MSI has attracted attention for its ability to analyze samples directly; however, improving spatial resolution remains a major technical challenge. Young Scientist developed a tapping-mode scanning probe electrospray ionization (t-SPESI) method that uniquely combines the core technologies of electrospray ionization (ESI) and atomic force microscopy (AFM). By using an oscillating capillary probe to periodically supply minute amounts of solvent to the sample surface, t-SPESI enables spatiotemporal separation of the extraction and ionization processes, allowing rapid, soft ionization of analytes in micro-regions of the sample. In addition, the oscillating probe senses the sample surface, minimizing the influence of surface topography on extraction and ionization during MSI. Young Scientist has further advanced high-spatial-resolution t-SPESI-MSI through the development of feedback-control methods, probe fabrication techniques, and miniaturization of t-SPESI units. This paper provides an overview of the progress made in the development of t-SPESI instrumentation and highlights MSI results obtained from tissues and single cells.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"521 ","pages":"Article 117569"},"PeriodicalIF":1.7,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145874131","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}
Stable electrospray ionization is crucial for ensuring consistent ion generation in mass spectrometry. Previously, a feedback control system based on spray current and Taylor cone angle was developed to automatically adjust the emitter voltage (Anal. Chem. 2023, 95, 28, 10744–10751). However, the system was susceptible to false signals caused by electrical noise, leakage, and discharge, and was not easy to implement in commercial ion sources. Here, we report a robust feedback system that relies solely on the optical image of the liquid meniscus condition at the emitter tip. A set of geometric parameters, including meniscus area, rectangularity, diameter-to-length ratio, and the degree of apex blurring, is extracted in real time from CCD images to identify the spraying mode and determine the required emitter voltage adjustment. The system maintains the Taylor cone shape within a target range, thereby preserving steady cone-jet operation under variations in flow rate, surface tension, and solvent composition. The feedback system was evaluated under both atmospheric and high-pressure ESI conditions. Under high-pressure operation, the system successfully stabilized the cone-jet mode even for pure water. The feedback-stabilized electrospray minimizes ion signal fluctuation caused by spray instability and may contribute to more reproducible ESI-MS analyses that reflect the true condition of the analyte in solution.
{"title":"Feedback control for electrospray ionization based on the shape of the liquid meniscus at the ESI emitter","authors":"Xiangting Chen , Qiangqiang Xie , Satoshi Ninomiya , Lee Chuin Chen","doi":"10.1016/j.ijms.2025.117567","DOIUrl":"10.1016/j.ijms.2025.117567","url":null,"abstract":"<div><div>Stable electrospray ionization is crucial for ensuring consistent ion generation in mass spectrometry. Previously, a feedback control system based on spray current and Taylor cone angle was developed to automatically adjust the emitter voltage (Anal. Chem. 2023, 95, 28, 10744–10751). However, the system was susceptible to false signals caused by electrical noise, leakage, and discharge, and was not easy to implement in commercial ion sources. Here, we report a robust feedback system that relies solely on the optical image of the liquid meniscus condition at the emitter tip. A set of geometric parameters, including meniscus area, rectangularity, diameter-to-length ratio, and the degree of apex blurring, is extracted in real time from CCD images to identify the spraying mode and determine the required emitter voltage adjustment. The system maintains the Taylor cone shape within a target range, thereby preserving steady cone-jet operation under variations in flow rate, surface tension, and solvent composition. The feedback system was evaluated under both atmospheric and high-pressure ESI conditions. Under high-pressure operation, the system successfully stabilized the cone-jet mode even for pure water. The feedback-stabilized electrospray minimizes ion signal fluctuation caused by spray instability and may contribute to more reproducible ESI-MS analyses that reflect the true condition of the analyte in solution.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"520 ","pages":"Article 117567"},"PeriodicalIF":1.7,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880441","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}
Pub Date : 2025-12-26DOI: 10.1016/j.ijms.2025.117568
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.2025.117568","DOIUrl":"10.1016/j.ijms.2025.117568","url":null,"abstract":"","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"520 ","pages":"Article 117568"},"PeriodicalIF":1.7,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880442","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}
Pub Date : 2025-12-24DOI: 10.1016/j.ijms.2025.117566
Justin Mak, Amin Famili, Christopher M. Crittenden
Structures for Lossless Ion Manipulation (SLIM) for high resolution ion mobility (HRIM) mass spectrometry has greatly enhanced resolution of isomers and compounds that challenge chromatography. However, in the current commercial setup consisting of a MOBIE SLIM coupled to an Agilent 6545XT, the upper limit of sensitive ion transmission is near m/z 4000.
We therefore aimed to overcome the truncated mass range because detecting large peptides, intact proteins, nucleic acids, and native complexes, as well as their aggregates, at lower charge states (higher m/z) increases spectral clarity of precursor ions, simplifies deconvolution, and can enrich sequencing coverage. Believing this was a solvable issue stemming from currently uncharacterized ion behavior, we investigated gas setup and DC potentials. Using cesium iodide and trastuzumab emtansine, our studies identified the importance of (1) increasing collision cell pressure, (2) reducing ion funnel source pressure, (3) placing the primary accelerating potential immediately before the ion trap (Trap Desolvation Delta), and (4) optimizing voltages in the Ion Beam Compressor. We also found that argon gas marginally increased signal intensities, suggesting that new hardware and electronics would be needed to further extend high-mass transmission. Taken together, our findings revise the current working theory of ion transmission in hybrid SLIM-MS systems—the primary accelerating potential must be applied immediately prior to the ion trap that accumulates ions for mobility separation instead of after the mobility separation—and serve as a more accurate user guide for higher m/z transmission.
{"title":"A framework for high-mass ion transmission in a hybrid SLIM-QTOF system","authors":"Justin Mak, Amin Famili, Christopher M. Crittenden","doi":"10.1016/j.ijms.2025.117566","DOIUrl":"10.1016/j.ijms.2025.117566","url":null,"abstract":"<div><div>Structures for Lossless Ion Manipulation (SLIM) for high resolution ion mobility (HRIM) mass spectrometry has greatly enhanced resolution of isomers and compounds that challenge chromatography. However, in the current commercial setup consisting of a MOBIE SLIM coupled to an Agilent 6545XT, the upper limit of sensitive ion transmission is near <em>m/z</em> 4000.</div><div>We therefore aimed to overcome the truncated mass range because detecting large peptides, intact proteins, nucleic acids, and native complexes, as well as their aggregates, at lower charge states (higher <em>m/z</em>) increases spectral clarity of precursor ions, simplifies deconvolution, and can enrich sequencing coverage. Believing this was a solvable issue stemming from currently uncharacterized ion behavior, we investigated gas setup and DC potentials. Using cesium iodide and trastuzumab emtansine, our studies identified the importance of (1) increasing collision cell pressure, (2) reducing ion funnel source pressure, (3) placing the primary accelerating potential immediately before the ion trap (Trap Desolvation Delta), and (4) optimizing voltages in the Ion Beam Compressor. We also found that argon gas marginally increased signal intensities, suggesting that new hardware and electronics would be needed to further extend high-mass transmission. Taken together, our findings revise the current working theory of ion transmission in hybrid SLIM-MS systems—the primary accelerating potential must be applied immediately prior to the ion trap that accumulates ions for mobility separation instead of after the mobility separation—and serve as a more accurate user guide for higher <em>m/z</em> transmission.</div></div>","PeriodicalId":338,"journal":{"name":"International Journal of Mass Spectrometry","volume":"520 ","pages":"Article 117566"},"PeriodicalIF":1.7,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837270","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}
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