Zelal Zuhal Kaya, Muhittin Serdar, Fehime Aksungar, Meltem Kilercik, Mustafa Serteser, Ahmet Tarik Baykal
{"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":"29 2","pages":"132-140"},"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}
{"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":"29 1","pages":"44-57"},"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}
{"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":"29 1","pages":"12-20"},"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}
Olivia L Duletski, Navamoney Arulsamy, Michael T Mock
{"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":"29 1","pages":"58-64"},"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}
{"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":"29 1","pages":"21-32"},"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}
{"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":"29 1","pages":"4"},"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}
{"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":"29 1","pages":"3"},"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}
{"title":"Unprecedented intact radical anions, closed shell anions, cluster ions, and traditional cations and radical cations by LIFDI-MS.","authors":"Mathias H Linden, H Bernhard Linden","doi":"10.1177/14690667221146079","DOIUrl":"https://doi.org/10.1177/14690667221146079","url":null,"abstract":"<p><p>Liquid injection field desorption ionization (LIFDI) proves the extraordinary softness of the ionization process combined with a convenient sample supply under the exclusion of moisture and air. LIFDI-mass spectrometry (MS) is used for organometallic and other seriously air-sensitive compounds forming intact ions without substantial fragmentation. Unprecedented molecular radical anions M<sup>-•</sup> are presented along with well-known intact M<sup>+•</sup> radical cations. Furthermore closed shell cations [C]<sup>+</sup> and adduct ions like [M + H]<sup>+</sup> or [M + Alkali]<sup>+</sup> are gently transferred from the solid emitter surface into the gas phase. Anions [A]<sup>-</sup> or [M - H]<sup>-</sup> are accessible by LIFDI-MS at medium field strengths. Ion pairs [C]<sup>+</sup>[A]<sup>-</sup> are separately detected by positive and negative mode LIFDI-MS, respectively. Here we give an overview of the different ion types accessible by LIFDI-MS. For the first time the field ionization/desorption of solar cell electron acceptor compounds is shown to deliver M<b><sup>-</sup></b><sup>•</sup> and M<b><sup>2-</sup></b><sup>•</sup> radical ions.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"29 1","pages":"5-11"},"PeriodicalIF":1.3,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9351405","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}
{"title":"Identification and characterization of selected silyl substituted silyl anions by liquid injection field desorption ionization mass spectrometry.","authors":"Thomas Lainer, Roland C Fischer, Michael Haas","doi":"10.1177/14690667221139720","DOIUrl":"https://doi.org/10.1177/14690667221139720","url":null,"abstract":"<p><p>Silyl anions are crucial building blocks in silicon chemistry and are frequently used in organosilicon chemistry. These so-called silanides are negatively charged three-coordinate species, isoelectronic to carbanions. In this contribution, we synthesized already literature known and unknown anionic silicon species. Here we focused on silyl substituted silyl anions with different substituted silicon atoms like hydrogen, methyl, and methoxy groups. Furthermore, we investigated these species with liquid injection field desorption ionization mass spectrometry.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"29 1","pages":"33-43"},"PeriodicalIF":1.3,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9701317","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}
{"title":"Positive + negative is not equal to zero: Use of negative ionisation as analyte identity confirmation tool in LC-ESI-MS analysis.","authors":"Ernesto Zapata, Ivo Leito, Koit Herodes","doi":"10.1177/14690667221130160","DOIUrl":"https://doi.org/10.1177/14690667221130160","url":null,"abstract":"<p><p>In this study the use of negative electrospray ionisation mode as a confirmation tool for identifying derivatized amino acids using LC-ESI-MS, was evaluated. The derivatization reagent was based on azobenzene N-hydroxysuccinimide carbamate. The results indicate that even though negative ionisation mode produced less intense peaks, the ratio of peak area of quantifier ion (obtained in positive mode) to the qualifier (or identifier) ion measured in negative mode meets the requirements established by two prominent validation guidelines: SANTE/11312/2021 and 2002/657/EC. Therefore, the use of product ions obtained via negative transitions as qualifier ions, while using product ions from positive transitions as quantifier ions is a fruitful approach that widens the choice of transitions to choose from for obtaining suitable qualifier ions. This methodology was applied to the LC-ESI-MS/MS determination of amino acids in different beverages (tomato juice, watermelon juice, kvass).</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"28 5-6","pages":"107-112"},"PeriodicalIF":1.3,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33490163","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}