European Journal of Mass Spectrometry最新文献

{"title":"Joseph John Thomson investigates the paranormal.","authors":"Kevin M Downard","doi":"10.1177/14690667211050599","DOIUrl":"https://doi.org/10.1177/14690667211050599","url":null,"abstract":"<p><p>Joseph John Thomson is best known for detecting two isotopes of neon within cathode ray tubes that lay the foundation of the field of mass spectrometry. He was awarded the 1906 Nobel Prize in Physics for the discovery of the electron and for his work on the conduction of electricity in gases in the same devices. He is less known for his strong religious beliefs and his interest in psychical research and the paranormal. Thomson served as a member of the Society for Psychical Research for over 50 years and even became its Vice President. During this time, he attended a number of séances and demonstrations by professed psychics and mediums. This article traces those who influenced his interest in the paranormal, from Balfour Stewart to Lord Rayleigh and William Crookes. It reports and illustrates his beliefs and experiences investigating the paranormal in his own words.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"27 5","pages":"151-157"},"PeriodicalIF":1.3,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39493740","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":"Vacuum ultraviolet photoionization and dissociative photoionization of toluene: Experimental and theoretical insights.","authors":"Yujie Zhao,&nbsp;Pei Huang,&nbsp;Li Li,&nbsp;Yousheng Zhan,&nbsp;Ke Wang,&nbsp;Haohang Yang,&nbsp;Jianhui Jin,&nbsp;Yuqian Chen,&nbsp;Yibao Liu,&nbsp;Liusi Sheng,&nbsp;Jun Chen,&nbsp;Maoqi Cao","doi":"10.1177/14690667211042707","DOIUrl":"https://doi.org/10.1177/14690667211042707","url":null,"abstract":"<p><p>The photoionization and dissociative photoionization of toluene have been studied using synchrotron radiation vacuum ultraviolet light with photon energy in the range of 8.50-25.50 eV. The ionization energies (8.82 eV) and double ionization energies (23.80 eV) of toluene as well as the appearance energies for its major fragments C₇H₇⁺ (11.17/10.71 eV), C₆H₅⁺ (13.73 eV), C₅H₆⁺ (13.58/12.50 eV), C₅H₅⁺ (16.23 eV), C₄H₅⁺ (15.64 eV), C₄H₄⁺ (16.10 eV) and C₄H₃⁺ (17.11 eV) are determined, respectively by using photoionization efficiency spectrometry. With the help of experimental and theoretical results, seven dissociative photoionization channels have been proposed: C₇H₇⁺ + H, C₆H₅⁺ + CH₃, C₅H₆⁺ + C₂H₂, C₅H₅⁺ + C₂H₂ + H, C₄H₅⁺ + C₃H₃, C₄H₄⁺ + C₃H₄ and C₄H₃⁺ + C₃H₄ + H. In addition, the geometries of the intermediates, transition states and products involved in these photoionization and dissociative photoionization processes have been performed at the B3LYP/6-311++G(d, p) level. The mechanisms of dissociative photoionization of toluene and the intermediates and transition states involved are discussed in detail. Generally speaking, the experimental results are in agreement with theoretical calculations in this work and published literature results. Especially the mechanisms of dissociative photoionization to C₄H₅⁺, C₄H₄⁺ and C₄H₃⁺ were discussed for the first time in this work. This investigation may provide useful information on understanding the photoionization and dissociative photoionization of toluene.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"27 5","pages":"166-180"},"PeriodicalIF":1.3,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39512923","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":"Proximity Effects in Mass Spectra of Benzanilides.","authors":"Nathan W Fenwick,&nbsp;Amie Saidykhan,&nbsp;Yasser Nazir,&nbsp;Richard Telford,&nbsp;Binyaameen Masood,&nbsp;William H C Martin,&nbsp;Richard T Gallagher,&nbsp;Richard D Bowen","doi":"10.1177/14690667211054152","DOIUrl":"https://doi.org/10.1177/14690667211054152","url":null,"abstract":"<p><p>The analytical value of peaks arising by a proximity effect in the electron ionization mass spectra of benzanilides has been established by examining the spectra of numerous examples of general structure XC₆H₄NHCOC₆H₄Y. Significant [M-X]⁺ signals are observed only when X = Cl, Br, I or CH₃O in the 2-position. The presence of strong [M-X]⁺ signals, but negligibly weak [M-Y]⁺ peaks, even when the C-Y bond would be expected to break more readily than the C-X bond, indicates that these diagnostically useful signals do not arise by simple cleavage. Similarly, the presence of an appreciable [M-Cl]⁺ signal, but no [M-Br]⁺ signal, in the spectra of representative examples of 4-Br-2ClC₆H₃NHCOC₆H₄Y, reveals that loss of a substituent from the 2-position occurs much more rapidly than fission of a weaker bond to a substituent in the 4-position. These trends are interpreted in terms of cyclization of the ionized 2-substituted benzanilide, followed by elimination of the substituent originally in the 2-position, to form a protonated 2-arylbenzoxazole.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"27 5","pages":"181-190"},"PeriodicalIF":1.3,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/b1/ba/10.1177_14690667211054152.PMC8586190.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39699764","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":"Certain Properties of a Generalized Class of Analytic Functions Involving Some Convolution Operator","authors":"F.S.A. Malik, Nusrat Ahmed Dar, Chitaranjan Sharma","doi":"10.34198/EJMS.7121.4976","DOIUrl":"https://doi.org/10.34198/EJMS.7121.4976","url":null,"abstract":"We use the concept of convolution to introduce and study the properties of a unified family \u0000 $mathcal{TUM}_gamma(g,b,k,alpha)$, \u0000 $(0leqgammaleq1,,kgeq0)$, \u0000 consisting of uniformly $k$-starlike and $k$-convex functions of \u0000 complex order $binmathbb{C}setminus{0}$ \u0000 and type $alphain[0,1)$.\u0000 The family $mathcal{TUM}_gamma(g,b,k,alpha)$ is a generalization of several other families of analytic functions available in literature.\u0000 Apart from discussing the coefficient bounds, sharp radii estimates, extreme points and the subordination theorem for this family, we settle down the Silverman's conjecture for integral means inequality. Moreover, invariance of this family under certain well-known integral operators is also established in this paper. Some previously known results are obtained as special cases.","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"1 1","pages":"49-76"},"PeriodicalIF":1.3,"publicationDate":"2021-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49519356","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":"Modeling of Extreme Crude Oil Price using the Generalized Pareto Distribution: Brent and West Texas Benchmark Price","authors":"Ngozi J. Amachukwu, H. Obiora-Ilouno, E. I. Obisue","doi":"10.34198/EJMS.6221.359374","DOIUrl":"https://doi.org/10.34198/EJMS.6221.359374","url":null,"abstract":"Background and objective: Crude oil is an essential commodity in many countries of the world. This work studies the risk involved in the extreme crude oil price, using the daily crude oil price of the Brent and the West Texas benchmark from year 1990 to 2019. Materials and methods: The Peak Over Threshold (POT) approach of the Generalized Pareto Distribution (GPD) was used to model the extreme crude oil price while the value at risk and the expected shortfall was used to quantify the risk involved in extreme price of crude oil. The GPD, using the Q-Q plot was found to be a good model for the extreme values of the crude oil price. Results: The Value at Risk (VaR) and the Expected Shortfall (ES) calculated at 90%, 95% and 99% with the Maximum Likelihood estimators of GPD parameters and the threshold values were found to decrease with increase in quantile for both benchmark. This shows that risk involved in extreme crude oil price will be borne only by the investors and public. Conclusion: It was also found that the VaR and ES of the Brent are higher than that of West Texas. This implies that it is safer to invest in West Texas crude oil.","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"1 1","pages":"359-374"},"PeriodicalIF":1.3,"publicationDate":"2021-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49305655","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":"Third Hankel Determinant Problem for Certain Subclasses of Analytic Functions Associated with Nephroid Domain","authors":"Muhammad Ghaffar Khan, B. Ahmad, W. K. Mashwani, T. G. Shaba, Muhammad Arif","doi":"10.34198/EJMS.6221.293308","DOIUrl":"https://doi.org/10.34198/EJMS.6221.293308","url":null,"abstract":"In this research article we consider two well known subclasses of starlike and bounded turning functions associated with nephroid domain. Our aims to find third Hankel determinant for these classes.","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"6 1","pages":"293-308"},"PeriodicalIF":1.3,"publicationDate":"2021-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43760078","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":"Separation, identification and characterization of stress degradation products of bortezomib using HPLC and LC-MS.","authors":"C Purushotham Reddy,&nbsp;K Ramakrishna,&nbsp;Kmv Narayana Rao","doi":"10.1177/14690667211006246","DOIUrl":"https://doi.org/10.1177/14690667211006246","url":null,"abstract":"<p><p>Bortezomib (BT) is a reversible inhibitor of proteasome which is used in the treatment of hematological cancers. To study the degradation behavior, BT was subjected to acidic, basic, neutral, photolytic, oxidative and thermal degradation conditions as per ICH guideline Q1A (R2). A gradient HPLC method has been developed for separating all the degradation products formed under various degradation conditions on Waters XBridge C₁₈ column (150 mm × 4.6 mm × 3.5 µm) using the mobile phase composed of ammonium formate and acetonitrile. A total of six degradation products were formed in various stress conditions and these were separated identified, and characterized using high performance liquid chromatography in combination with electrospray ionization tandem mass spectrometric studies.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"27 2-4","pages":"115-125"},"PeriodicalIF":1.3,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/14690667211006246","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25570631","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 of newly formed toxic chemicals in E-cigarette aerosols with Orbitrap mass spectrometry and implications on E-cigarette control.","authors":"Beizhan Yan,&nbsp;Dimitri Zagorevski,&nbsp;Vesna Ilievski,&nbsp;Norman J Kleiman,&nbsp;Diane B Re,&nbsp;Ana Navas-Acien,&nbsp;Markus Hilpert","doi":"10.1177/14690667211040207","DOIUrl":"https://doi.org/10.1177/14690667211040207","url":null,"abstract":"<p><p>The increasing use of electronic nicotine delivery systems (ENDS) is of concern due to multiple emerging adverse health effects. Most analyses of the harmful chemicals of ENDS have targeted metals or carbonyls generated by thermal decomposition of carrier liquids such as propylene glycol. However, new complex compounds not routinely identified and with unknown health consequences could be formed. ENDS aerosol samples were collected by the direct aerosol droplet deposition method. Untargeted analysis was performed using Orbitrap mass spectrometry with high mass accuracy. We identified more than 30 \"features\" in the aerosol characterized by pairs of the mass-to-charge ratio \"<i>m</i>/<i>z</i>\" of the compound and the retention time. We identified several compounds containing nicotine and propylene glycol (NIC-PG), whose abundance relative to nicotine increased along with vaping power used. On the basis of the prediction by the Environmental Protection Agency Toxicity Estimation Software Tool, these compounds exert developmental toxicity. In addition, a nitrogen-containing compound, likely tributylamine (a known lung irritant), was identified based on the molecular weight. This compound has not been previously identified in ENDS e-liquids and aerosols. ENDS produce not only small toxic compounds such as aldehydes, but also large complex toxic compounds such as NIC-PG. Predicted development toxicity for NIC-PG is concerning for fetal development in pregnant women who use ENDS, children exposed to secondhand or thirdhand ENDS aerosols, and teenage ENDS users whose brains are still developing. The strong positive association between NIC-PG levels and ENDS power output supports regulating high-powered ENDS.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"27 2-4","pages":"141-148"},"PeriodicalIF":1.3,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9035225/pdf/nihms-1795867.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39357323","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":"Gas-phase generation of dinuclear Au(I)-Au(II) complexes by laser desorption ionization mass spectrometry.","authors":"Małgorzata Kasperkowiak,&nbsp;Michalina Durnik,&nbsp;Wojciech Jankowski,&nbsp;Marcin Hoffmann,&nbsp;Błażej Gierczyk,&nbsp;Rafał Frański","doi":"10.1177/14690667211028785","DOIUrl":"https://doi.org/10.1177/14690667211028785","url":null,"abstract":"<p><p>Alkali metal chloroaurates(III) were analysed by laser desorption ionization mass spectrometry. Among a number of generated gas-phase ionic clusters, the unusual ions [MAu₂Cl₅]^- (were M stands for Na, K, Rb, Cs) were detected. The spectra of metastable ions and quantum mechanics calculations show the presence of unprecedented Au(I)-Au(II) interactions in the clusters.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"27 2-4","pages":"101-106"},"PeriodicalIF":1.3,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/14690667211028785","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39120074","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":"Establishment of validated stability indicating purity method based on the stress degradation behavior of gonadotropin-releasing hormone antagonist (ganirelix) in an injectable formulation using HPLC and LC-MS-QTOF.","authors":"Kumarswamy Ummiti,&nbsp;J V Shanmukha Kumar","doi":"10.1177/14690667211005335","DOIUrl":"https://doi.org/10.1177/14690667211005335","url":null,"abstract":"<p><p>Stress study of a drug substance or pharmaceutical drug product provides a vision into degradation pathways and degradation products of the active pharmaceutical ingredient and helps in interpretation of the chemical structure of the degradation impurities. In the current study, Ganirelix active ingredient presented in the Orgalutran® was stressed with acidic and alkali hydrolysis, photolysis, thermal and oxidation conditions as per the guidelines of International Conference on Harmonization (ICH) Q1A (R2). Ganirelix was found to be labile under thermal and alkali hydrolytic stress conditions, while it was stable to acid hydrolytic, oxidative and photolytic stress. All degradation products were separated with a resolution > 1.5 on a C18 column (2.6 µm, 25 cm×4.6 mm) using a hydrophilic ion pair such as sodium perchlorate, at a concentration <0.04 M. In total, four major degradant impurities were found during stress study. These impurities were fractionated and desalted by flash chromatography for identification of chemical structures. LC-MS-QTOF analysis revealed that two degradation products are diastereomers of Ganirelix, one degradation product is a deamination compound and other degradation product result from the insertion of a new amino acid residue in the Ganirelix peptide sequence. The developed method is sensitive enough to quantify the related substances of Ganirelix at the 0.04% level with that of Ganirelix test concentration.</p>","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":"27 2-4","pages":"126-140"},"PeriodicalIF":1.3,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/14690667211005335","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25564730","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}