Pub Date : 2023-04-01Epub Date: 2023-03-15DOI: 10.1177/14690667231164552
Anton Lioznov, Evgeny Nikolaev
The Fourier transform ion cyclotron resonance method holds the lead in mass accuracy and resolving power among all other mass spectrometry methods. The dynamically harmonized cell is largely responsible for the supremacy. This cell has an ideal hyperbolic trapping potential after averaging over fast cyclotron motion. Recently we have introduced an open modification of the cell (especially useful with ultrahigh magnetic fields) and have found the analytical solution for the averaged potential inside it. The voltage on specific "regularizing" electrodes determines how close a potential is to the hyperbolic one. In this article, we find the optimal voltage on these "regularizing" electrodes analytically. This will assist with both further analysis and tuning of the trap after manufacturing.
{"title":"The analytical solution for the optimum voltage on regularizing electrodes of the open dynamically harmonized cell.","authors":"Anton Lioznov, Evgeny Nikolaev","doi":"10.1177/14690667231164552","DOIUrl":"10.1177/14690667231164552","url":null,"abstract":"<p><p>The Fourier transform ion cyclotron resonance method holds the lead in mass accuracy and resolving power among all other mass spectrometry methods. The dynamically harmonized cell is largely responsible for the supremacy. This cell has an ideal hyperbolic trapping potential after averaging over fast cyclotron motion. Recently we have introduced an open modification of the cell (especially useful with ultrahigh magnetic fields) and have found the analytical solution for the averaged potential inside it. The voltage on specific \"regularizing\" electrodes determines how close a potential is to the hyperbolic one. In this article, we find the optimal voltage on these \"regularizing\" electrodes analytically. This will assist with both further analysis and tuning of the trap after manufacturing.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9601816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.1177/14690667231165876
Jürgen Grotemeyer
{"title":"Prof. Dr Michael Przybylski (* 25.3.1948; † 27.2.2023).","authors":"Jürgen Grotemeyer","doi":"10.1177/14690667231165876","DOIUrl":"https://doi.org/10.1177/14690667231165876","url":null,"abstract":"","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9587638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.1177/14690667231164096
Mpho Mafata, Maria Stander, Keabetswe Masike, Astrid Buica
Applied sciences have increased focus on omics studies which merge data science with analytical tools. These studies often result in large amounts of data produced and the objective is to generate meaningful interpretations from them. This can sometimes mean combining and integrating different datasets through data fusion techniques. The most strategic course of action when dealing with products of unknown profile is to use exploratory approaches. For omics, this means using untargeted analytical methods and exploratory data analysis techniques. The current study aimed to perform data fusion on untargeted multimodal (negative and positive mode) liquid chromatography-high-resolution mass spectrometry data using multiple factor analysis. The data fusion results were interpreted using agglomerative hierarchical clustering on biplot projections. The study reduced the thousands of spectral signals processed to less than a hundred features (a primary parameter combination of retention time and mass-to-charge ratios, RT_m/z). The correlations between cluster members (samples and features from) were calculated and the top 10% highly correlated features were identified for each cluster. These features were then tentatively identified using secondary parameters (drift time, ion mobility constant and collision cross-section values) from the ion mobility spectra. These ion mobility (secondary) parameters can be used for future studies in wine chemical analysis and added to the growing list of annotated chemical signals in applied sciences.
{"title":"Exploratory data fusion of untargeted multimodal LC-HRMS with annotation by LCMS-TOF-ion mobility: White wine case study.","authors":"Mpho Mafata, Maria Stander, Keabetswe Masike, Astrid Buica","doi":"10.1177/14690667231164096","DOIUrl":"https://doi.org/10.1177/14690667231164096","url":null,"abstract":"<p><p>Applied sciences have increased focus on omics studies which merge data science with analytical tools. These studies often result in large amounts of data produced and the objective is to generate meaningful interpretations from them. This can sometimes mean combining and integrating different datasets through data fusion techniques. The most strategic course of action when dealing with products of unknown profile is to use exploratory approaches. For omics, this means using untargeted analytical methods and exploratory data analysis techniques. The current study aimed to perform data fusion on untargeted multimodal (negative and positive mode) liquid chromatography-high-resolution mass spectrometry data using multiple factor analysis. The data fusion results were interpreted using agglomerative hierarchical clustering on biplot projections. The study reduced the thousands of spectral signals processed to less than a hundred features (a primary parameter combination of retention time and mass-to-charge ratios, RT_m/z). The correlations between cluster members (samples and features from) were calculated and the top 10% highly correlated features were identified for each cluster. These features were then tentatively identified using secondary parameters (drift time, ion mobility constant and collision cross-section values) from the ion mobility spectra. These ion mobility (secondary) parameters can be used for future studies in wine chemical analysis and added to the growing list of annotated chemical signals in applied sciences.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10068406/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9601254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-01DOI: 10.1177/14690667231153616
Zelal Zuhal Kaya, Muhittin Serdar, Fehime Aksungar, Meltem Kilercik, Mustafa Serteser, Ahmet Tarik Baykal
Introduction: Serum free light chain (FLC) measurements are increasingly prominent for patients with plasma cell disorders (PCDs) in screening, prognostic stratification, and monitoring therapy responses. Objectives: We aimed to develop a sensitive, reliable, and accurate method for diagnosing PCDs that can notably decrease the time and cost of current methods. Methods: Here, we present a novel approach for FLC measurement using immunoenrichment on micro-affinity chromatography in combination with matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) detection. In this study, serum free kappa (κ) and free lambda (λ) light chain (LC) levels in the serum of 105 patients were compared between the nephelometric serum FLC quantification and MALDI-TOF MS detection. Results: Cohen's kappa coefficient between the MALDI-TOF MS-based method and the FLC assay revealed an almost perfect agreement in the case of normal (negative) results (κ = 0.92; 95% confidence interval (CI): 0.837 to 0.968) and a good agreement in the case of increased (positive) results (κ = 0.76; 95% CI: 0.608 to 0.870). In Spearman's correlation analysis, the best correlation was found between serum free κ/λ ratios (r = 0.628, 0.496 to 0.732; p <0.0001). Our method showed sensitivity (92.5%) and specificity (76.3%) for discrimination between the κ/λ FLC ratio compared to the serum FLC assay. Conclusion: The proposed method can significantly contribute to diagnosing and monitoring PCDs as it can significantly be time-saving, cost-effective in FLC measurement.
{"title":"Rapid detection of serum free light chains by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.","authors":"Zelal Zuhal Kaya, Muhittin Serdar, Fehime Aksungar, Meltem Kilercik, Mustafa Serteser, Ahmet Tarik Baykal","doi":"10.1177/14690667231153616","DOIUrl":"https://doi.org/10.1177/14690667231153616","url":null,"abstract":"<p><p><b>Introduction:</b> Serum free light chain (FLC) measurements are increasingly prominent for patients with plasma cell disorders (PCDs) in screening, prognostic stratification, and monitoring therapy responses. <b>Objectives:</b> We aimed to develop a sensitive, reliable, and accurate method for diagnosing PCDs that can notably decrease the time and cost of current methods. <b>Methods:</b> Here, we present a novel approach for FLC measurement using immunoenrichment on micro-affinity chromatography in combination with matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) detection. In this study, serum free kappa (κ) and free lambda (λ) light chain (LC) levels in the serum of 105 patients were compared between the nephelometric serum FLC quantification and MALDI-TOF MS detection. <b>Results:</b> Cohen's kappa coefficient between the MALDI-TOF MS-based method and the FLC assay revealed an almost perfect agreement in the case of normal (negative) results (κ = 0.92; 95% confidence interval (CI): 0.837 to 0.968) and a good agreement in the case of increased (positive) results (κ = 0.76; 95% CI: 0.608 to 0.870). In Spearman's correlation analysis, the best correlation was found between serum free κ/λ ratios (r = 0.628, 0.496 to 0.732; <i>p</i> <0.0001). Our method showed sensitivity (92.5%) and specificity (76.3%) for discrimination between the κ/λ FLC ratio compared to the serum FLC assay. <b>Conclusion:</b> The proposed method can significantly contribute to diagnosing and monitoring PCDs as it can significantly be time-saving, cost-effective in FLC measurement.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9238069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-01DOI: 10.1177/14690667221137465
Leonard R Maurer, Marianne Engeser
Although showing fascinating chemical properties and reactivity in solution, heavier tetrelylidyne complexes with M≡E triple bonds have not been studied in the gas phase before due to their high sensitivity towards air and moisture. We selected four group 6 germylidyne complexes, [Cp(PMe3)2M≡GeArMes] (M = Mo (1-Mo), W (1-W), ArMes = 2,6-dimesitylphenyl) and [Tp'(CO)2M≡GeArMes] (M = Mo (2-Mo), W (2-W), Tp' = κ3-N,N',N''-hydridotris(3,5-dimethylpyrazolyl) borate), for a mass-spectrometric study. Liquid Injection Field Desorption Ionization (LIFDI) proved to be a well-suited technique to ionize these sensitive compounds as the spectra show the molecular ions as radical cations and only minor traces of fragmentation or degradation products. In addition, Atmospheric Pressure Chemical Ionization (APCI) connected to a high-resolving tandem mass spectrometer allowed us to study the gas-phase fragmentation behaviour of these compounds. The fragmentation patterns not only comprise the expected losses of phosphane or carbonyl ligands, respectively, but also indicate C-H bond activation by the electron-deficient metal centre. An enhanced reactivity of the tungsten species is visible in a preferred methyl abstraction in the phosphane complex 1-W compared to 1-Mo. Although degradation in solution before ionization obviously can destroy the M≡Ge triple bond, the cleavage of the M≡Ge bond upon gas-phase activation is not observed for the Mo species and only as a minor pathway for the W compounds, highlighting the high bonding energy between metal and tetrel.
虽然在溶液中表现出迷人的化学性质和反应活性,但由于具有M≡E三键的较重的四烷基炔配合物对空气和水分的高度敏感性,以前还没有在气相中研究过。我们选择了四个6组的germylidyne配合物,[Cp(PMe3)2M≡GeArMes] (M = Mo (1-Mo), W (1-W), ArMes = 2,6-基苯基)和[Tp'(CO)2M≡GeArMes] (M = Mo (2-Mo), W (2-W), Tp' = κ3-N,N',N' -氢化(3,5-二甲基吡唑基)硼酸盐)进行质谱研究。液体注入场解吸电离(LIFDI)被证明是一种非常适合电离这些敏感化合物的技术,因为光谱显示分子离子为自由基阳离子,只有少量碎片或降解产物的痕迹。此外,大气压化学电离(APCI)连接到高分辨率串联质谱仪使我们能够研究这些化合物的气相破碎行为。碎片化模式不仅分别包含磷烷或羰基配体的预期损失,而且还表明C-H键被缺电子金属中心激活。与1-Mo相比,在磷化配合物1-W中首选的甲基抽象中,钨的反应性增强。虽然电离前在溶液中的降解可以明显地破坏M≡Ge三键,但在Mo化合物中未观察到M≡Ge键在气相活化时的裂解,而W化合物仅作为次要途径,突出了金属和四萜之间的高键能。
{"title":"Group 6 germylidyne complexes in the gas phase by LIFDI and APCI mass spectrometry.","authors":"Leonard R Maurer, Marianne Engeser","doi":"10.1177/14690667221137465","DOIUrl":"https://doi.org/10.1177/14690667221137465","url":null,"abstract":"<p><p>Although showing fascinating chemical properties and reactivity in solution, heavier tetrelylidyne complexes with M≡E triple bonds have not been studied in the gas phase before due to their high sensitivity towards air and moisture. We selected four group 6 germylidyne complexes, [Cp(PMe<sub>3</sub>)<sub>2</sub>M≡GeAr<sup>Mes</sup>] (M = Mo (<b>1-Mo</b>), W (<b>1-W</b>), Ar<sup>Mes</sup> = 2,6-dimesitylphenyl) and [Tp'(CO)<sub>2</sub>M≡GeAr<sup>Mes</sup>] (M = Mo (<b>2-Mo</b>), W (<b>2-W</b>), Tp' = κ<sup>3</sup>-<i>N,N',N''</i>-hydridotris(3,5-dimethylpyrazolyl) borate), for a mass-spectrometric study. Liquid Injection Field Desorption Ionization (LIFDI) proved to be a well-suited technique to ionize these sensitive compounds as the spectra show the molecular ions as radical cations and only minor traces of fragmentation or degradation products. In addition, Atmospheric Pressure Chemical Ionization (APCI) connected to a high-resolving tandem mass spectrometer allowed us to study the gas-phase fragmentation behaviour of these compounds. The fragmentation patterns not only comprise the expected losses of phosphane or carbonyl ligands, respectively, but also indicate C-H bond activation by the electron-deficient metal centre. An enhanced reactivity of the tungsten species is visible in a preferred methyl abstraction in the phosphane complex <b>1-W</b> compared to <b>1-Mo</b>. Although degradation in solution before ionization obviously can destroy the M≡Ge triple bond, the cleavage of the M≡Ge bond upon gas-phase activation is not observed for the Mo species and only as a minor pathway for the W compounds, highlighting the high bonding energy between metal and tetrel.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9346155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-01DOI: 10.1177/14690667221146687
Nils Boysen, Anjana Devi
Electron ionization mass spectrometry (EI-MS) is often used to characterize volatile and thermally stable organometallic complexes relevant for chemical vapor deposition (CVD) processes. However, this method has limitations for thermally unstable and labile organometallic complexes. In this context, EI-MS is not the preferred method of choice for characterizing such compounds. With three different representative organometallic complexes based on the transition metals yttrium, iridium, and silver, relevant as precursors for CVD of different materials, the significance of liquid injection field desorption/ionization mass spectrometry (LIFDI-MS) as an important precursor characterization tool is exemplified. The precursors are not only reactive toward ambient air, but also thermally labile especially in the case of iridium and silver complexes. As a promising alternative, LIFDI-MS is used to overcome the limitations of EI-MS. For the first time, these complexes were successfully analyzed using LIFDI-MS. The comparison between EI-MS and LIFDI-MS highlights that LIFDI-MS is superior for the mass spectrometric analysis of sensitive and labile complexes. In terms of precursor characterization, LIFDI-MS can be fully exploited to gain valuable insights into the decomposition mechanisms and identifying the nuclearity of organometallic precursors used for CVD applications.
{"title":"Liquid injection field desorption/ionization as a powerful tool to characterize volatile, labile, and reactive metal-organic complexes.","authors":"Nils Boysen, Anjana Devi","doi":"10.1177/14690667221146687","DOIUrl":"https://doi.org/10.1177/14690667221146687","url":null,"abstract":"<p><p>Electron ionization mass spectrometry (EI-MS) is often used to characterize volatile and thermally stable organometallic complexes relevant for chemical vapor deposition (CVD) processes. However, this method has limitations for thermally unstable and labile organometallic complexes. In this context, EI-MS is not the preferred method of choice for characterizing such compounds. With three different representative organometallic complexes based on the transition metals yttrium, iridium, and silver, relevant as precursors for CVD of different materials, the significance of liquid injection field desorption/ionization mass spectrometry (LIFDI-MS) as an important precursor characterization tool is exemplified. The precursors are not only reactive toward ambient air, but also thermally labile especially in the case of iridium and silver complexes. As a promising alternative, LIFDI-MS is used to overcome the limitations of EI-MS. For the first time, these complexes were successfully analyzed using LIFDI-MS. The comparison between EI-MS and LIFDI-MS highlights that LIFDI-MS is superior for the mass spectrometric analysis of sensitive and labile complexes. In terms of precursor characterization, LIFDI-MS can be fully exploited to gain valuable insights into the decomposition mechanisms and identifying the nuclearity of organometallic precursors used for CVD applications.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9716391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-01DOI: 10.1177/14690667221149498
Olivia L Duletski, Navamoney Arulsamy, Michael T Mock
We report the synthesis of molybdenum and tungsten bromo dicarbonyl complexes (POCOPtBu)MIIBr(CO)2 (M = Mo or W; POCOPtBu = κ3-C6H3-1,3-[OP(tBu)2]2) supported by an anionic PCP pincer ligand, and the chromium complex (PNPtBu)Cr0(CO)3 (PNPtBu = 2,6-bis(di-tert-butyl-phosphinomethyl)pyridine) bearing a neutral PNP pincer scaffold. The three group six complexes described in this study have been characterized by Liquid Injection Field Desorption Ionization Mass Spectrometry (LIFDI-MS), NMR, and IR spectroscopy. Single crystal X-ray diffraction studies show the MoII and WII complexes adopt a six-coordinate distorted trigonal prismatic geometry, whereas the Cr0 complex exhibits a distorted octahedral geometry.
{"title":"Synthesis, characterization, and liquid injection field desorption ionization mass spectrometry analysis of pincer ligated group 6 (Cr, Mo, W) carbonyl complexes.","authors":"Olivia L Duletski, Navamoney Arulsamy, Michael T Mock","doi":"10.1177/14690667221149498","DOIUrl":"https://doi.org/10.1177/14690667221149498","url":null,"abstract":"<p><p>We report the synthesis of molybdenum and tungsten bromo dicarbonyl complexes (POCOP<i><sup>t</sup></i><sup>Bu</sup>)M<sup>II</sup>Br(CO)<sub>2</sub> (M = Mo or W; POCOP<i><sup>t</sup></i><sup>Bu</sup> = κ<sup>3</sup>-C<sub>6</sub>H<sub>3</sub>-1,3-[OP(<i>t</i>Bu)<sub>2</sub>]<sub>2</sub>) supported by an anionic PCP pincer ligand, and the chromium complex (PNP<i><sup>t</sup></i><sup>Bu</sup>)Cr<sup>0</sup>(CO)<sub>3</sub> (PNP<i><sup>t</sup></i><sup>Bu</sup> = 2,6-bis(di-<i>tert</i>-butyl-phosphinomethyl)pyridine) bearing a neutral PNP pincer scaffold. The three group six complexes described in this study have been characterized by Liquid Injection Field Desorption Ionization Mass Spectrometry (LIFDI-MS), NMR, and IR spectroscopy. Single crystal X-ray diffraction studies show the Mo<sup>II</sup> and W<sup>II</sup> complexes adopt a six-coordinate distorted trigonal prismatic geometry, whereas the Cr<sup>0</sup> complex exhibits a distorted octahedral geometry.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9339542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-01DOI: 10.1177/14690667221133388
Jürgen H Gross
Field desorption (FD) traditionally is an ionization technique in mass spectrometry (MS) that is performed in high vacuum. So far only two studies have explored FD at atmospheric pressure or even superatmospheric pressure, respectively. This work pursues ion desorption from 13-µm activated tungsten emitters at atmospheric pressure. The emitters are positioned in front of the atmospheric pressure interface of a Fourier transform-ion cyclotron resonance (FT-ICR) mass spectrometer and the entrance electrode of the interface is set to 3-5 kV with respect to the emitter. Under these conditions positive, and for the first time, negative ion desorption is achieved. In either polarity, atmospheric pressure field desorption (APFD) is robust and spectra are reproducible. Both singly charged positive and negative ions formed by these processes are characterized by accurate mass-based formula assignments and in part by tandem mass spectrometry. The compounds analyzed include the ionic liquids trihexyl(tetradecyl) phosphonium tris(pentafluoroethyl) trifluorophosphate) and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, the acidic compounds perfluorononanoic acid and polyethylene glycol diacid, as well as two amino-terminated polypropylene glycols. Some surface mobility on the emitter is prerequisite for ion desorption to occur. While ionic liquids inherently provide this mobility, the desorption of ions from solid analytes requires the assistance of a liquid matrix, e.g. glycerol.
{"title":"Desorption of positive and negative ions from activated field emitters at atmospheric pressure.","authors":"Jürgen H Gross","doi":"10.1177/14690667221133388","DOIUrl":"https://doi.org/10.1177/14690667221133388","url":null,"abstract":"<p><p>Field desorption (FD) traditionally is an ionization technique in mass spectrometry (MS) that is performed in high vacuum. So far only two studies have explored FD at atmospheric pressure or even superatmospheric pressure, respectively. This work pursues ion desorption from 13-µm activated tungsten emitters at atmospheric pressure. The emitters are positioned in front of the atmospheric pressure interface of a Fourier transform-ion cyclotron resonance (FT-ICR) mass spectrometer and the entrance electrode of the interface is set to 3-5 kV with respect to the emitter. Under these conditions positive, and for the first time, negative ion desorption is achieved. In either polarity, atmospheric pressure field desorption (APFD) is robust and spectra are reproducible. Both singly charged positive and negative ions formed by these processes are characterized by accurate mass-based formula assignments and in part by tandem mass spectrometry. The compounds analyzed include the ionic liquids trihexyl(tetradecyl) phosphonium tris(pentafluoroethyl) trifluorophosphate) and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, the acidic compounds perfluorononanoic acid and polyethylene glycol diacid, as well as two amino-terminated polypropylene glycols. Some surface mobility on the emitter is prerequisite for ion desorption to occur. While ionic liquids inherently provide this mobility, the desorption of ions from solid analytes requires the assistance of a liquid matrix, e.g. glycerol.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9903004/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9402359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-01DOI: 10.1177/14690667221146486
H Bernhard Linden
Liquid Injection Field Desorption Ionization (LIFDI) Mass Spectrometry (MS) became increasingly attractive to catalytic, inorganic, and organometallic chemists publishing more than 500 papers with LIFDI data during the last years. The extremely soft ionization of neutral compounds, the compatibility with non-polar solvents like toluene or hexane and last but not least the quick and convenient protocol under anaerobic conditions made LIFDI MS the method of choice for reactive compounds sensitive to air and/or moisture. The softness of the ionization is due to the fact that LIFDI is one of three Field Ionization (FI) methods which remove the weakest bound electron from neutral molecules literally without transferring excess energy to the hence stable radical ions. FI-MS was introduced by Inghram and Gomer in 1955 as the first of these methods (DOI: 10.1021/ja01607a096). FI mass spectra of hydrocarbons were essentially free of fragment ion peaks as opposed to Electron Ionization (EI) spectra. This made FI become a standard ionization method in the petrochemical industry. FI and EI have in common that only gases and vapours of compounds can be ionized. Therefore, the term FI-MS was soon associated with soft ionization mass spectrometry for the analysis of gases and volatile compounds. Field Desorption (FD) was introduced in 1969 by my venerated teacher Hans Dieter Beckey (DOI: 10.1016/ 0020-7381(69)80047-1). Using FI, he observed raising signal intensities along with the aging of the emitter wire. The notable increase in ionization efficiency was found to be correlated with the growth of tiny graphite whiskers via decomposition of acetone vapour on the hot surface of the wire. This process during tuning of the ion source raised the local field strength this strongly that up to 100 times more intensive signals appeared. When Beckey dipped a solution of D-Glucose onto an aged, i.e., “high sensitivity” wire, reinstalled the source flange, pumped down, and acquired the first FD spectra, he obtained the [M+H] ion signal as the base peak while fragment ion intensities remained at a negligible level. Thus, according to the title of the first FD paper, FD became the first ionization method for “the study of thermally unstable substances of low volatility”. LIFDI was introduced here in EJMS in 2004 (DOI: 10.1255/ejms.655). LIFDI outperforms FD by its convenient sample supply to the emitter right inside the ion source through a fused silica capillary without breaking the vacuum. LIFDI enabled a fully anaerobic protocol with the capillary aspirating sample solution under the inert headspace of a septum capped vial or directly out of the glove box (DOI: 10.1021/jacsau.1c00117). In conclusion, LIFDI, FD, and FI share the soft ionization of neutral molecules by “removal of electrons from any species by interaction with a high electrical field” (according to UPAC 1997). They differ in the way the samples are supplied to the emitter: in FI via the gas phase, in FD f
{"title":"Guest Editorial: Two Decades of LIFDI: Pedigree and Capabilities.","authors":"H Bernhard Linden","doi":"10.1177/14690667221146486","DOIUrl":"https://doi.org/10.1177/14690667221146486","url":null,"abstract":"Liquid Injection Field Desorption Ionization (LIFDI) Mass Spectrometry (MS) became increasingly attractive to catalytic, inorganic, and organometallic chemists publishing more than 500 papers with LIFDI data during the last years. The extremely soft ionization of neutral compounds, the compatibility with non-polar solvents like toluene or hexane and last but not least the quick and convenient protocol under anaerobic conditions made LIFDI MS the method of choice for reactive compounds sensitive to air and/or moisture. The softness of the ionization is due to the fact that LIFDI is one of three Field Ionization (FI) methods which remove the weakest bound electron from neutral molecules literally without transferring excess energy to the hence stable radical ions. FI-MS was introduced by Inghram and Gomer in 1955 as the first of these methods (DOI: 10.1021/ja01607a096). FI mass spectra of hydrocarbons were essentially free of fragment ion peaks as opposed to Electron Ionization (EI) spectra. This made FI become a standard ionization method in the petrochemical industry. FI and EI have in common that only gases and vapours of compounds can be ionized. Therefore, the term FI-MS was soon associated with soft ionization mass spectrometry for the analysis of gases and volatile compounds. Field Desorption (FD) was introduced in 1969 by my venerated teacher Hans Dieter Beckey (DOI: 10.1016/ 0020-7381(69)80047-1). Using FI, he observed raising signal intensities along with the aging of the emitter wire. The notable increase in ionization efficiency was found to be correlated with the growth of tiny graphite whiskers via decomposition of acetone vapour on the hot surface of the wire. This process during tuning of the ion source raised the local field strength this strongly that up to 100 times more intensive signals appeared. When Beckey dipped a solution of D-Glucose onto an aged, i.e., “high sensitivity” wire, reinstalled the source flange, pumped down, and acquired the first FD spectra, he obtained the [M+H] ion signal as the base peak while fragment ion intensities remained at a negligible level. Thus, according to the title of the first FD paper, FD became the first ionization method for “the study of thermally unstable substances of low volatility”. LIFDI was introduced here in EJMS in 2004 (DOI: 10.1255/ejms.655). LIFDI outperforms FD by its convenient sample supply to the emitter right inside the ion source through a fused silica capillary without breaking the vacuum. LIFDI enabled a fully anaerobic protocol with the capillary aspirating sample solution under the inert headspace of a septum capped vial or directly out of the glove box (DOI: 10.1021/jacsau.1c00117). In conclusion, LIFDI, FD, and FI share the soft ionization of neutral molecules by “removal of electrons from any species by interaction with a high electrical field” (according to UPAC 1997). They differ in the way the samples are supplied to the emitter: in FI via the gas phase, in FD f","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9346169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-01DOI: 10.1177/14690667221148578
Jürgen Grotemeyer
{"title":"Editorial.","authors":"Jürgen Grotemeyer","doi":"10.1177/14690667221148578","DOIUrl":"https://doi.org/10.1177/14690667221148578","url":null,"abstract":"","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9346025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}