Journal of Mass Spectrometry最新文献

{"title":"Tandem mass spectrometry of homologous 3-hydroxyfurazan and nitrile amino acids: Analysis of cooperative interactions and fragmentation processes","authors":"J. Stuart Grossert,&nbsp;Andrew M. J. Crowell,&nbsp;Donatella Boschi,&nbsp;Marco L. Lolli,&nbsp;Robert L. White","doi":"10.1002/jms.5043","DOIUrl":"10.1002/jms.5043","url":null,"abstract":"<p>The assignment of structure by tandem mass spectrometry (MS/MS) relies on the interpretation of the fragmentation behavior of gas-phase ions. Mass spectra were acquired for a series of heterocyclic mimetics of acidic amino acids and a related series of nitrile amino acids. All amino acids were readily protonated or deprotonated by electrospray ionization (ESI), and distinctive fragmentation processes were observed when the ions were subjected to collision-induced dissociation (CID). The deprotonated heterocycles showed bond cleavages of the 3-hydroxyfurazan ring with formation of oxoisocyanate and the complementary deprotonated nitrile amino acid. Further fragmentation of the deprotonated nitrile amino acids was greatly dependent on the length of the alkyl nitrile side chain. Competing losses of CO₂ versus HCN occurred from α-cyanoglycinate (shortest chain), whereas water was lost from 2-amino-5-cyanopentanoate (longest chain). Interestingly, loss of acrylonitrile by a McLafferty-type fragmentation process was detected for 2-amino-4-cyanobutanoate, and several competing processes were observed for β-cyanoalanate. In one process, cyanide ion was formed either by consecutive losses of ammonia, carbon dioxide, and acetylene or by a one-step decarboxylative elimination. In another, complementary ions were obtained from β-cyanoalanate by loss of acetonitrile or HN=CHCO₂H. Fragmentation of the protonated 3-hydroxyfurazan and nitrile amino acids resulted in the cumulative loss (H₂O + CO), a loss that is commonly observed for protonated aliphatic α-amino acids. Overall, the distinct fragmentation behavior of the multifunctional 3-hydroxyfurazan amino acids correlated with the charged site, whereas fragmentations of the deprotonated nitrile amino acids showed cooperative interactions between the nitrile and the carboxylate groups.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jms.5043","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141093495","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":"On the fate of protonated chloroformates in the gas phase: a competition between forming HCl and chloroformic acid","authors":"Malick Diedhiou,&nbsp;Paul M. Mayer","doi":"10.1002/jms.5044","DOIUrl":"10.1002/jms.5044","url":null,"abstract":"<p>Chloroformates are prevalent in the atmosphere due to their utilization as fuel additives and industrial solvents. These species may undergo interactions with atmospheric water resulting in protonated chloroformates. This study delves into the gas-phase dissociation of these protonated species. Tandem mass spectrometry was employed to scrutinize the unimolecular dissociation of protonated methyl (<b>1</b>), ethyl (<b>2</b>), neopentyl (<b>3</b>), and phenyl chloroformate (<b>4</b>). Notably, <b>1</b> and <b>4</b> exhibited HCl loss, yielding CH₃OCO⁺ and C₆H₅OCO⁺, respectively, with <b>1</b> additionally generating neutral methanol and ClCO⁺. <b>4</b> additionally loses CO and CO₂. In contrast, <b>2</b> and <b>3</b> each only exhibit a single fragmentation channel, with <b>2</b> losing C₂H₄ to generate protonated chloroformic acid and <b>3</b> generating protonated 2-methylbutene by losing neutral chloroformic acid. Density functional theory at the B3LYP/6-311+G(d,p) level of theory was employed to explore minimum energy reaction pathways for each ion, and CBS-QB3 single-point energy calculations were added to provide reliable energetics. The Rice–Ramsperger–Kassel–Marcus (RRKM) calculations of the rate constants for selected competing processes were carried out to link theory and experiment. One common unimolecular process observed was the 1,3-H shift of the proton from the carbonyl oxygen to the ester oxygen before dissociation.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jms.5044","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141071325","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":"Charge-solvated versus protonated salt forms of cyclodepsipeptide toxins in electrospray: Dissociation of alkali-cationized forms enables straightforward sequencing of cereulide","authors":"Sophie Liuu,&nbsp;Kam eng Trinh,&nbsp;Ekaterina Darii,&nbsp;Chenqin Cao,&nbsp;Annelaure Damont,&nbsp;Yves Gimbert,&nbsp;François Fenaille,&nbsp;Yassine Makni,&nbsp;Chanthadary Inthavong,&nbsp;Gwenaëlle Lavison-Bompard,&nbsp;Jacques-Antoine Hennekinne,&nbsp;Olivier Firmesse,&nbsp;Jean-Claude Tabet","doi":"10.1002/jms.5037","DOIUrl":"10.1002/jms.5037","url":null,"abstract":"<p><i>Bacillus cereus</i> is responsible for foodborne outbreaks worldwide. Among the produced toxins, cereulide induces nausea and vomiting after 30 min to 6 h following the consumption of contaminated foods. Cereulide, a cyclodepsipeptide, is an ionophore selective to K⁺ in solution. In electrospray, the selectivity is reduced as [M + Li]⁺; [M + Na]⁺ and [M + NH₄]⁺ can also be detected without adding corresponding salts. Two forms are possible for alkali-cationized ions: <i>charge-solvated</i> (CS) that exclusively dissociates by releasing a bare alkali ion and <i>protonated salt</i> (PS), yielding alkali product ions by covalent bond cleavages (CBC) promoted by mobile proton. Based on a modified peptide cleavage nomenclature, the PS product ion series (<b>b</b>, <b>a</b>, [<b>b</b> + H₂O] and [<b>b</b> + C_nH_2nO] [<i>n</i> = 4, 5]) are produced by Na⁺/Li⁺/K⁺-cationized cereulide species that specifically open at ester linkages followed by proton mobilization promoting competitive ester CBC as evidenced under resonant collision activation. What is more, unlike the sodiated or lithiated cereulide, which regenerates little or no alkali cation, the potassiated forms lead to an abundant K⁺ regeneration. This occurs by splitting of (i) the potassiated CS forms with an appearance threshold close to that of the PS first fragment ion generation and (ii) eight to four potassiated residue product ions from the PS forms. Since from Na⁺/Li⁺-cationized cereulide, (i) the negligible Na⁺/Li⁺ regeneration results in a higher sensibility than that of potassiated forms that abundantly releasing K⁺, and (ii) a better sequence recovering, the use of Na⁺ (or Li⁺) should be more pertinent to sequence isocereulides and other cyclodepsipeptides.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jms.5037","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140945196","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":"Determination of vancomycin and meropenem in serum and synovial fluid of patients with prosthetic joint infections using UPLC–MS/MS","authors":"Jiawei He,&nbsp;Jing Wang,&nbsp;Li Cao,&nbsp;Xiaogang Zhang,&nbsp;Guoqing Li,&nbsp;Boyong Xu,&nbsp;Baochao Ji,&nbsp;Jun Zhao,&nbsp;Junjie Huang,&nbsp;Jianhua Yang","doi":"10.1002/jms.5041","DOIUrl":"10.1002/jms.5041","url":null,"abstract":"<p>Numerous studies have suggested that intra-articular administration of antibiotics following primary revision surgery may be one of the methods for treating prosthetic joint infection (PJI). Vancomycin and meropenem are the two most commonly used antibiotics for local application. Determining the concentrations of vancomycin and meropenem in the serum and synovial fluid of patients with PJI plays a significant role in further optimizing local medication schemes and effectively eradicating biofilm infections. This study aimed to establish a rapid, sensitive, and accurate ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method for determining the concentrations of vancomycin and meropenem in human serum and synovial fluid. Serum samples were processed using acetonitrile precipitation of proteins and dichloromethane extraction, while synovial fluid samples were diluted before analysis. Chromatographic separation was achieved in 6 min on a Waters Acquity UPLC BEH C18 column, with the mobile phase consisting of 0.1% formic acid in water (solvent A) and acetonitrile (solvent B). Quantification was carried out using a Waters XEVO TQD triple quadrupole mass spectrometer with an electrospray ionization (ESI) source in positive ion mode. The multiple reaction monitoring (MRM) mode was employed to detect the following quantifier ion transitions: 717.95–99.97 (norvancomycin), 725.90–100.04 (vancomycin), 384.16–67.99 (meropenem). The method validation conformed to the guidelines of the FDA and the Chinese Pharmacopoeia. The method demonstrated good linearity within the range of 0.5–50 μg/ml for serum and 0.5–100 μg/ml for synovial fluid. Selectivity, intra-day and inter-day precision and accuracy, extraction recovery, matrix effect, and stability validation results all met the required standards. This method has been successfully applied in the pharmacokinetic/pharmacodynamic (PK/PD) studies of patients with PJI.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140945197","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":"Insights into modifiers effects in differential mobility spectrometry: A data science approach for metabolomics and peptidomics","authors":"Stepan Stepanovic,&nbsp;Lysi Ekmekciu,&nbsp;Bandar Alghanem,&nbsp;Gérard Hopfgartner","doi":"10.1002/jms.5039","DOIUrl":"10.1002/jms.5039","url":null,"abstract":"<p>Utilizing a data-driven approach, this study investigates modifier effects on compensation voltage in differential mobility spectrometry–mass spectrometry (DMS-MS) for metabolites and peptides. Our analysis uncovers specific factors causing signal suppression in small molecules and pinpoints both signal suppression mechanisms and the analytes involved. In peptides, machine learning models discern a relationship between molecular weight, topological polar surface area, peptide charge, and proton transfer-induced signal suppression. The models exhibit robust performance, offering valuable insights for the application of DMS to metabolites and tryptic peptides analysis by DMS-MS.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jms.5039","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140922432","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":"Direct sub-atmospheric pressure ionization mass spectrometry: Evaporation/sublimation-driven ionization is amazing, fundamentally, and practically","authors":"Sarah Trimpin,&nbsp;Ellen D. Inutan,&nbsp;Vincent S. Pagnotti,&nbsp;Santosh Karki,&nbsp;Darrell D. Marshall,&nbsp;Khoa Hoang,&nbsp;Beixi Wang,&nbsp;Christopher B. Lietz,&nbsp;Alicia L. Richards,&nbsp;Frank S. Yenchick,&nbsp;Chuping Lee,&nbsp;I-Chung Lu,&nbsp;Madeleine Fenner,&nbsp;Sara Madarshahian,&nbsp;Sarah Saylor,&nbsp;Nicolas D. Chubatyi,&nbsp;Teresa Zimmerman,&nbsp;Abigail Moreno-Pedraza,&nbsp;Tongwen Wang,&nbsp;Adetoun Adeniji-Adele,&nbsp;Anil K. Meher,&nbsp;Hasini Madagedara,&nbsp;Zachary Owczarzak,&nbsp;Ahmed Musavi,&nbsp;Tamara L. Hendrickson,&nbsp;Patricia M. Peacock,&nbsp;John W. Tomsho,&nbsp;Barbara S. Larsen,&nbsp;Laszlo Prokai,&nbsp;Vladimir Shulaev,&nbsp;Milan Pophristic,&nbsp;Charles N. McEwen","doi":"10.1002/jms.5018","DOIUrl":"10.1002/jms.5018","url":null,"abstract":"<p>This paper covers direct sub-atmospheric pressure ionization mass spectrometry (MS). The discovery, applications, and mechanistic aspects of novel ionization processes for use in MS that are not based on the high-energy input from voltage, laser, and/or high temperature but on sublimation/evaporation within a region linking a higher to lower pressure and modulated by heat and collisions, are discussed, including how this new reality has guided a series of discoveries, instrument developments, and commercialization. A research focus, inter alia, is on how best to understand, improve, and use these novel ionization processes, which convert volatile and nonvolatile compounds from solids (sublimation) or liquids (evaporation) into gas-phase ions for analysis by MS providing reproducible, accurate, sensitive, and prompt results. Our perception on how these unprecedented versus traditional ionization processes/methods relate to each other, how they can be made to coexist on the same mass spectrometer, and an outlook on new and expanded applications (e.g., clinical, portable, fast, safe, and autonomous) is presented, and is based on ST's Opening lecture presentation at the Nordic Mass spectrometry Conference, Geilo, Norway, January 2023. Focus will be on matrix-assisted ionization (MAI) and solvent-assisted ionization (SAI) MS covering the period from 2010 to 2023; a potential paradigm shift in the making.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140911562","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":"CCSfind: A tool for chemically informed LC-IM-MS database building","authors":"Sangeeta Kumari,&nbsp;Tim Causon","doi":"10.1002/jms.5040","DOIUrl":"10.1002/jms.5040","url":null,"abstract":"<p>In addition to providing critical knowledge of the accurate mass of ions, ion mobility-mass spectrometry (IM-MS) delivers complementary data relating to the conformation and size of ions in the form of an ion mobility spectrum and derived parameters, namely, the ion's mobility (<i>K</i>) and the IM-derived collision cross section (<i>CCS</i>). However, the maximum amount of information obtained in IM-MS measurements is not currently transferred into analytical databases including the full mobility spectra (<i>CCS</i> distributions) as well as capturing of additional ion species (e.g., adducts) into the same compound entry. We introduce CCSfind, a new tool for building comprehensive databases from experimental IM-MS measurements of small molecules. CCSfind allows predicted ion species to be chosen for input chemical formulae, which are then targeted by CCSfind after parsing open source mzML input files to provide a unified set of results within a single data processing step. CCSfind can handle both chromatographically separated isomers and IM separation of isomeric ions (e.g., “protomers” or conformers of the same ion species) with simple user control over the output for new database entries in SQL format. Files of up to 1 GB can be processed in less than 2 min on a desktop computer with 32 GB RAM with computational time scaling linearly with the size of the input mzML file or the number of input molecular formulae. Results are manually reviewed, annotated with experimental settings, before committing the database where the full dataset can be retrieved.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jms.5040","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140911307","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":"In-Electrospray source Hydrogen/Deuterium exchange coupled to multistage fragmentation for the investigation of the protonation and fragmentation pathways of gas phase ions","authors":"Yury Kostyukevich,&nbsp;Sergey Osipenko,&nbsp;Liudmila Borisova,&nbsp;Albert Kireev","doi":"10.1002/jms.5032","DOIUrl":"10.1002/jms.5032","url":null,"abstract":"<p>Identification of molecules in complex natural matrices relies on matching the fragmentation spectra of ions under investigation and the spectra acquired for the corresponding analytical standards. Currently, there are many databases of experimentally measured tandem mass spectrometry spectra (such as NIST, MzCloud, and Metlin), and considerable progress has been made in the development of software for predicting tandem mass spectrometry fragments in silico using combinatorial, machine learning, and quantum chemistry approaches (such as MetFrag, CFM-ID, and QCxMS). However, the electrospray ionization molecules can be ionized at different sites (protonated or deprotonated), and the fragmentation spectra of such ions are different. Here, we are using the combination of the in-ESI source hydrogen/deuterium exchange reaction and MSⁿ fragmentation for the investigation of the fragmentation pathways for different protomers of organic molecules. It is shown that the distribution of the deuterium in the fragment ions reflects the presence of different protomers. For several molecules, the distribution of deuterium was traced up to the MS⁵ level of fragmentation revealing many unusual and unexpected effects. For example, we investigated the loss of HF from the ciprofloxacin and norfloxacin ions and observed that for ions protonated at –COOH group, the eliminating hydrogen always comes from –NH group. When ions are protonated at another site, the elimination of hydrogen with a probability of 30% occurs from the –NH group, and with a probability of 70%, it originates from other sites on the molecule. Such effects were not described previously. Quantum chemical simulation was used for the verification of the protonated structures and simulation of the corresponding fragmentation spectra.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140911564","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":"Intercropping with maize and sorghum-induced saikosaponin accumulation in Bupleurum chinense DC. by liquid chromatography-mass spectrometry-based metabolomics","authors":"Rui Zhang,&nbsp;Xiangchuan Li,&nbsp;Jixu Qu,&nbsp;Doudou Zhang,&nbsp;Linxu Cao,&nbsp;Xuemei Qin,&nbsp;Zhenyu Li","doi":"10.1002/jms.5035","DOIUrl":"10.1002/jms.5035","url":null,"abstract":"<p>Bupleuri Radix is an important medicinal plant, which has been used in China and other Asian countries for thousands of years. Cultivated <i>Bupleurum chinense</i> DC. (<i>B. chinense</i>) is the main commodity of Bupleuri Radix. The benefits of intercropping with various crops for <i>B. chinense</i> have been recognized; however, the influence of intercropping on the chemical composition of <i>B. chinense</i> is still unclear yet. In this study, intercropping with sorghum and maize exhibited little effect on the root length, root diameter, and single root mass of <i>B. chinense</i>. Only the intercropping with sorghum increased the root length of <i>B. chinense</i> slightly compared to the monocropping. In addition, 200 compounds were identified by UHPLC-Q-TOF-MS, and metabolomic combined with the Venn diagram and heatmap analysis showed apparent separation between the intercropped and monocropped <i>B. chinense</i> samples. Intercropping with sorghum and maize could both increase the saikosaponins, fatty acyls, and organic acids in <i>B. chinense</i> while decreasing the phospholipids. The influence of intercropping on the saikosaponin biosynthesis was probably related with the light intensity and hormone levels in <i>B. chinense</i>. Moreover, we found intercropping increased the anti-inflammatory activity of <i>B. chinense</i>. This study provides a scientific reference for the beneficial effect of intercropping mode of <i>B. chinense</i>.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140897672","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":"Modeling of a linear ion trap with driving rectangular waveforms","authors":"A. I. Ivanov,&nbsp;A. A. Sysoev,&nbsp;A. N. Konenkov,&nbsp;N. V. Konenkov","doi":"10.1002/jms.5030","DOIUrl":"10.1002/jms.5030","url":null,"abstract":"<p>We consider the operation of a digital linear ion trap with resonant radial ejection. A sequence of rectangular voltage pulses with a dipole resonance signal is applied to the trap electrodes. The periodic waveform is piecewise constant, has zero mean, and is determined by an asymmetry parameter <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>d</mi>\u0000 </mrow>\u0000 <annotation>$$ d $$</annotation>\u0000 </semantics></math>: one value is taken on interval <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mfenced>\u0000 <mn>0</mn>\u0000 <mi>dT</mi>\u0000 </mfenced>\u0000 </mrow>\u0000 <annotation>$$ left(0, dTright) $$</annotation>\u0000 </semantics></math> and another on <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mfenced>\u0000 <mi>dT</mi>\u0000 <mi>T</mi>\u0000 </mfenced>\u0000 </mrow>\u0000 <annotation>$$ left( dT,Tright) $$</annotation>\u0000 </semantics></math>, where <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>T</mi>\u0000 </mrow>\u0000 <annotation>$$ T $$</annotation>\u0000 </semantics></math> is the RF period. Ion mass scanning is performed by varying the asymmetry parameter <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>d</mi>\u0000 </mrow>\u0000 <annotation>$$ d $$</annotation>\u0000 </semantics></math> and amplitude of the negative pulse part with time. The ion oscillation frequencies and acceptance of the linear trap are calculated. The dependence of the ion mass to charge ratio <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>m</mi>\u0000 <mo>/</mo>\u0000 <mi>z</mi>\u0000 </mrow>\u0000 <annotation>$$ m/z $$</annotation>\u0000 </semantics></math> on the parameter <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>d</mi>\u0000 </mrow>\u0000 <annotation>$$ d $$</annotation>\u0000 </semantics></math> is <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>m</mi>\u0000 <mo>/</mo>\u0000 <mi>z</mi>\u0000 <mo>~</mo>\u0000 <msup>\u0000 <mi>d</mi>\u0000 <mn>2</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$$ m/zsim {d}^2 $$</annotation>\u0000 </semantics></math>. The maximum value is about <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>m</mi>\u0000 <mo>/</mo>\u0000 <mi>z</mi>\u0000 <mo>=</mo>\u0000 <mn>30</mn>\u0000 </mrow>\u0000 <annotatio","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140897601","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}