{"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}
{"title":"Gas Chromatography - Ion Mobility Spectrometry as a tool for quick detection of hazardous volatile organic compounds in indoor and ambient air: A university campus case study.","authors":"Pedro Catalão Moura, Valentina Vassilenko","doi":"10.1177/14690667221130170","DOIUrl":"https://doi.org/10.1177/14690667221130170","url":null,"abstract":"<p><p>Society's concerns about the citizens<b>'</b> exposure to possibly dangerous environments have recently risen; nevertheless, the assessment of indoor air quality still represents a major contemporary challenge. The volatile organic compounds (VOCs) are among the main factors responsible for deteriorating air quality conditions. These analytes are very common in daily-use environments and they can be extremely hazardous to human health, even at trace concentrations levels. For these reasons, their quick detection, identification, and quantification are crucial tasks, especially for indoor and heavily-populated scenarios, where the exposure time is usually quite long. In this work, a Gas Chromatography - Ion Mobility Spectrometry (GC-IMS) device was used for continuous monitoring indoor and ambient air environments at a large-scale, due to its outstanding levels of sensibility, selectivity, analytical flexibility, and almost real-time monitoring capability. A total of 496 spectra were collected from 15 locations of a university campus and posteriorly analysed. Overall, 23 compounds were identified among the 31 detected. Some of them, like Ethanol and 2-Propanol, were reported as being very hazardous to the human organism, especially in indoor environments. The achieved results confirmed the suitability of GC-IMS technology for air quality assessment and monitoring of VOCs and, more importantly, proved how dangerous indoor environments can be in scenarios of continuous exposure.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"28 5-6","pages":"113-126"},"PeriodicalIF":1.3,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9647320/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33489775","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}
Kai Cheng, Junsong Wei, Jianrong Kou, Huining You, Min Li, Weiyi Feng
{"title":"Quantitative evaluation and pharmacokinetic characteristics of the irreversible BTK inhibitor zanubrutinib in mouse plasma using LC-MS/MS.","authors":"Kai Cheng, Junsong Wei, Jianrong Kou, Huining You, Min Li, Weiyi Feng","doi":"10.1177/14690667221128934","DOIUrl":"https://doi.org/10.1177/14690667221128934","url":null,"abstract":"<p><p>Zanubrutinib (BGB-3111) belongs to the class of irreversible inhibitors of Bruton's tyrosine kinase (BTK) for treating B-cell malignancies. A validated assay with excellent sensitivity, selectivity, and simplicity is required to measure plasma concentration and investigate its pharmacokinetics. The plasma of mice containing zanubrutinib and roxithromycin (internal standard) was processed with acetonitrile for protein precipitation. Then the supernatant was analyzed by high-performance liquid chromatography coupled with a triple quadrupole mass spectrometer using electrospray ionization in the positive mode. Zanubrutinib was given to mice intragastrically at 30 mg/kg to determine its pharmacokinetic parameters. The method was verified and showed good linearity in the range of 0.1-100 ng/mL. The method's sensitivity, accuracy, and precision were all within acceptable bounds. By this method, the pharmacokinetic profile of zanubrutinib in mouse plasma was measured.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"28 3-4","pages":"81-88"},"PeriodicalIF":1.3,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33478312","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}
Özge Özer, E. Nemutlu, Tuba Reçber, C. C. Eylem, B. Aktaş, S. Kır, A. Kars, S. Aksoy
{"title":"Liquid biopsy markers for early diagnosis of brain metastasis patients with breast cancer by metabolomics","authors":"Özge Özer, E. Nemutlu, Tuba Reçber, C. C. Eylem, B. Aktaş, S. Kır, A. Kars, S. Aksoy","doi":"10.1177/14690667221093871","DOIUrl":"https://doi.org/10.1177/14690667221093871","url":null,"abstract":"Introduction: Breast cancer is the most common cancer in women and is the second most common cause of cancer related mortality. Metabolomics, the identification of small metabolites, is a technique for determining the amount of these metabolites. Objectives: This study aimed to identify markers for the early diagnosis of brain metastasis by metabolomic methods in breast cancer patients. Methods: A total of 88 breast cancer patients with distant metastases were included in the study. The patients were divided into two groups according to their metastasis status: patients with brain metastases and distant metastases without any brain metastases. Liquid chromatography quadrupole time-of-flight mass spectrometry (LC-qTOF-MS) and gas chromatography-mass spectrometry (GC-MS) analysis methods were used for metabolomic analyses. Results: 33 of them, 88 patients had brain metastasis, and 55 patients had distant metastases without brain metastasis. A total of 72 and 35 metabolites were identified by the GC-MS and LC-qTOF-MS analysis, respectively. 47 of them were found to be significantly different in patients with brain metastasis. The pathway analysis, performed with significantly altered metabolites, showed that aminoacyl tRNA biosynthesis, valine, leucine and isoleucine biosynthesis, alanine, aspartate, and glutamate metabolism, arginine biosynthesis, glycine, serine, and threonine metabolism pathways significantly altered in patients with brain metastasis. Predictive accuracies for have identifying the brain metastasis were performed with receiver operating characteristic (ROC) analysis, and the model with fifteen metabolites has 96.9% accuracy. Conclusions: While these results should be supported by prospective studies, these data are promising for early detection of brain metastasis with markers in liquid biopsy samples.","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"28 1","pages":"56 - 64"},"PeriodicalIF":1.3,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48467504","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}
Emily Yii Ling Wong, Gabriel Onn Kit Loh, Chen Zhu Goh, Y. Tan, Sharon Shi Min Ng, Kian Boon Law, Kit Yee Cheah, Hani Farhana Mohd, K. Peh
{"title":"Sample preparation and quantification of polar drug, allopurinol, in human plasma using LCMSMS","authors":"Emily Yii Ling Wong, Gabriel Onn Kit Loh, Chen Zhu Goh, Y. Tan, Sharon Shi Min Ng, Kian Boon Law, Kit Yee Cheah, Hani Farhana Mohd, K. Peh","doi":"10.1177/14690667221105837","DOIUrl":"https://doi.org/10.1177/14690667221105837","url":null,"abstract":"A fast, selective and reproducible LC-MS/MS method with simple sample preparation was developed and validated for a polar compound, allopurinol in human plasma, using acyclovir as internal standard (IS). Chromatographic separation was achieved using Agilent Poroshell 120 EC-C18 (100 × 2.1 mmID, 2.7 µm) analytical column. The mobile phase was comprised of 0.1%v/v formic acid-methanol (95:05; v/v), at a flow rate of 0.45 mL/min. The effect of different protein precipitation agents used in sample preparation such as methanol, acetonitrile, a mixture of acetonitrile-methanol and a mixture of acetonitrile-acetone were evaluated to optimize the extraction efficiency of allopurinol and IS. The use of acetone-acetonitrile (50:50, v/v) as protein precipitating agent shortened the sample preparation time and improved the recovery of allopurinol to above 93%. The IS-normalised matrix factors at two concentration levels were 1.0, with CV of 5.1% and 4.2%. Allopurinol in plasma was stable at benchtop for 24 h, in autosampler tray for 48 h, in instrumentation room for 48 h, in freezer after 7 freeze-thaw cycles and in freezer for 140 days. Allopurinol stock standard solutions were stable for 140 days at room temperature and in the chiller. The short sample run time of the validated bioanalytical method allowed high throughput analysis of plasma samples in pharmacokinetic study of an allopurinol formulation. The robustness and reproducibility of the bioanalytical method was reaffirmed through incurred sample reanalysis (ISR).","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"28 1","pages":"35 - 46"},"PeriodicalIF":1.3,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46436838","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}