European Journal of Mass Spectrometry最新文献_第10页

Modeling of Extreme Crude Oil Price using the Generalized Pareto Distribution: Brent and West Texas Benchmark Price 使用广义帕累托分布的极端原油价格建模：布伦特和西德克萨斯基准价格

IF 1.3 4区化学

European Journal of Mass Spectrometry Pub Date : 2021-04-28 DOI: 10.34198/EJMS.6221.359374

Ngozi J. Amachukwu, H. Obiora-Ilouno, E. I. Obisue

{"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":null,"pages":null},"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}

引用次数: 0

Third Hankel Determinant Problem for Certain Subclasses of Analytic Functions Associated with Nephroid Domain 与Nephroid域相关的解析函数的某些子类的第三Hankel行列式问题

IF 1.3 4区化学

European Journal of Mass Spectrometry Pub Date : 2021-04-09 DOI: 10.34198/EJMS.6221.293308

Muhammad Ghaffar Khan, B. Ahmad, W. K. Mashwani, T. G. Shaba, Muhammad Arif

引用次数: 2

Separation, identification and characterization of stress degradation products of bortezomib using HPLC and LC-MS. 硼替佐米应力降解产物的HPLC和LC-MS分离鉴定及表征。

IF 1.3 4区化学

European Journal of Mass Spectrometry Pub Date : 2021-04-01 Epub Date: 2021-04-07 DOI: 10.1177/14690667211006246

C Purushotham Reddy, K Ramakrishna, Kmv Narayana Rao

引用次数: 0

Identification of newly formed toxic chemicals in E-cigarette aerosols with Orbitrap mass spectrometry and implications on E-cigarette control. Orbitrap质谱法鉴定电子烟气溶胶中新形成的有毒化学物质及其对电子烟控制的影响。

IF 1.3 4区化学

European Journal of Mass Spectrometry Pub Date : 2021-04-01 Epub Date: 2021-08-27 DOI: 10.1177/14690667211040207

Beizhan Yan, Dimitri Zagorevski, Vesna Ilievski, Norman J Kleiman, Diane B Re, Ana Navas-Acien, Markus Hilpert

{"title":"Identification of newly formed toxic chemicals in E-cigarette aerosols with Orbitrap mass spectrometry and implications on E-cigarette control.","authors":"Beizhan Yan, Dimitri Zagorevski, Vesna Ilievski, Norman J Kleiman, Diane B Re, Ana Navas-Acien, Markus Hilpert","doi":"10.1177/14690667211040207","DOIUrl":"https://doi.org/10.1177/14690667211040207","url":null,"abstract":"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 \"m/z\" 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.","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"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}

引用次数: 6

Gas-phase generation of dinuclear Au(I)-Au(II) complexes by laser desorption ionization mass spectrometry. 激光解吸电离质谱法气相生成双核Au(I)-Au(II)配合物。

IF 1.3 4区化学

European Journal of Mass Spectrometry Pub Date : 2021-04-01 Epub Date: 2021-06-29 DOI: 10.1177/14690667211028785

Małgorzata Kasperkowiak, Michalina Durnik, Wojciech Jankowski, Marcin Hoffmann, Błażej Gierczyk, Rafał Frański

引用次数: 1

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. 基于促性腺激素释放激素拮抗剂(ganirelix)在注射制剂中的应激降解行为，采用HPLC和LC-MS-QTOF建立了经过验证的稳定性指示纯度方法。

IF 1.3 4区化学

European Journal of Mass Spectrometry Pub Date : 2021-04-01 Epub Date: 2021-04-07 DOI: 10.1177/14690667211005335

Kumarswamy Ummiti, J V Shanmukha Kumar

{"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, J V Shanmukha Kumar","doi":"10.1177/14690667211005335","DOIUrl":"https://doi.org/10.1177/14690667211005335","url":null,"abstract":"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.","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"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}

引用次数: 3

A simulation study of excitation contour of a linear trap with spatial harmonics. 具有空间谐波的线性阱激励轮廓的仿真研究。

IF 1.3 4区化学

European Journal of Mass Spectrometry Pub Date : 2021-04-01 Epub Date: 2021-05-26 DOI: 10.1177/14690667211020153

N V Konenkov

引用次数: 2

Silicon surface assisted laser desorption ionization mass spectrometry for quantitative analysis. 硅表面辅助激光解吸电离质谱法定量分析。

IF 1.3 4区化学

European Journal of Mass Spectrometry Pub Date : 2021-04-01 Epub Date: 2021-04-04 DOI: 10.1177/14690667211006017

Alexander A Grechnikov, Alexey S Borodkov, Yaroslav O Simanovsky, Sergey M Nikiforov

{"title":"Silicon surface assisted laser desorption ionization mass spectrometry for quantitative analysis.","authors":"Alexander A Grechnikov, Alexey S Borodkov, Yaroslav O Simanovsky, Sergey M Nikiforov","doi":"10.1177/14690667211006017","DOIUrl":"https://doi.org/10.1177/14690667211006017","url":null,"abstract":"The approach to quantitative analysis by silicon Surface Assisted Laser Desorption Ionization Mass Spectrometry (Si-SALDI) is proposed. The approach is based on the new method for forming an active surface layer on a silicon substrate by exposing to laser radiation directly in the ion source of a mass spectrometer. The method can be used repeatedly on the same substrate, providing high reproducibility of its surface ionization properties and high ionization efficiency of organic compounds. Within the proposed approach, the methods of improvement of signal reproducibility are also considered, including continuous monitoring of the silicon surface ionization properties using a Knudsen effusion cell; scanning the surface of a silicon substrate with a laser beam; selecting the optimal value of laser fluence and using a reproducible sample introduction technique. It is demonstrated that this approach can be successfully applied to quantify clinically relevant concentrations of pharmaceutical drugs in extracts of blood.","PeriodicalId":12007,"journal":{"name":"European Journal of Mass Spectrometry","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/14690667211006017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25561984","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}

引用次数: 2

Characterization of anthocyanin from red sorghum (Sorghum bicolor) bran by liquid chromatography-electron spray ionization mass spectrometry analysis. 液相色谱-电子喷雾质谱分析表征红高粱(高粱双色)麸皮中花青素的含量。

IF 1.3 4区化学

European Journal of Mass Spectrometry Pub Date : 2021-04-01 Epub Date: 2021-07-29 DOI: 10.1177/14690667211035720

P Suganyadevi, M Saravanakumar, S Mohandas

引用次数: 1

Theoretical fractional formulation of a three-dimensional radio frequency ion trap (Paul-trap) for optimum mass separation. 用于最佳质量分离的三维射频离子阱(保罗阱)的理论分数公式。

IF 1.3 4区化学

European Journal of Mass Spectrometry Pub Date : 2021-04-01 Epub Date: 2021-07-04 DOI: 10.1177/14690667211026790

Sarkhosh Seddighi Chaharborj, Shahriar Seddighi Chaharborj, Zahra Seddighi Chaharborj, Pei See Phang

引用次数: 0