Monatshefte für Chemie / Chemical Monthly最新文献_第8页

Factorial design-assisted spectrophotometric methods for the determination of total catechins in green tea extract via reaction with MBTH. Application to commercial tablet 通过与 MBTH 反应测定绿茶提取物中总儿茶素的因子设计辅助分光光度法。应用于商业片剂

Monatshefte für Chemie / Chemical Monthly Pub Date : 2024-02-21 DOI: 10.1007/s00706-024-03177-5

{"title":"Factorial design-assisted spectrophotometric methods for the determination of total catechins in green tea extract via reaction with MBTH. Application to commercial tablet","authors":"","doi":"10.1007/s00706-024-03177-5","DOIUrl":"https://doi.org/10.1007/s00706-024-03177-5","url":null,"abstract":"<h3>Abstract</h3> Green tea extract (GTE) is a supplement derived from the green tea plant which aids in weight loss along with other innumerable health. New analytical methods for determining GTE via its catechins using a design-assisted spectrophotometric methodologies are provided. The procedures are based on the formation of orange-colored products that are detectable at 473 or 455 nm, respectively, when catechins react with MBTH in the presence of FeCl3 (method I) or K2S2O8 (method II). Critical parameters were optimized using design of experiments (DOE). The absorbance-concentration plots were rectilinear over the ranges 4.0–20.0 or 4.0–40.0 µg cm−3 with limits of detection 0.393 or 0.493 µg cm−3 for methods I & II, respectively. Our methods were applied to pure catechins in GTE, namely (-)-epicatechin and (-)-epigallocatechin gallate. Moreover, the proposed methods were perfectly applied to the analysis of GTE in a commercial tablet. Good agreement between the collected data and those of the reported approach demonstrating that there were no significant variations. According to International Council for Harmonization (ICH) Guidelines, the procedures were validated. <h3>Graphical abstract</h3> <img alt=\"\" src=\"https://static-content.springer.com/image/MediaObjects/706_2024_3177_Figa_HTML.png\"/> ","PeriodicalId":19011,"journal":{"name":"Monatshefte für Chemie / Chemical Monthly","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139923934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of pressing pressure on the capacity of recycled graphite anode 加压对再生石墨阳极容量的影响

Monatshefte für Chemie / Chemical Monthly Pub Date : 2024-02-20 DOI: 10.1007/s00706-024-03174-8

引用次数: 0

MWCNTs-supported Ni electrocatalyst-modified CPE as a sensing platform for voltammetric determination of ibuprofen in pharmaceutical formulations 以 MWCNTs 为支撑的 Ni 电催化剂修饰的 CPE 作为传感平台，用于伏安法测定药物制剂中的布洛芬

Monatshefte für Chemie / Chemical Monthly Pub Date : 2024-02-16 DOI: 10.1007/s00706-023-03158-0

Ana D. Đurović, Vuk V. Gudelj, Sanja N. Panić, Snežana Ž. Kravić, Lukáš Richtera, Zorica S. Stojanović

{"title":"MWCNTs-supported Ni electrocatalyst-modified CPE as a sensing platform for voltammetric determination of ibuprofen in pharmaceutical formulations","authors":"Ana D. Đurović, Vuk V. Gudelj, Sanja N. Panić, Snežana Ž. Kravić, Lukáš Richtera, Zorica S. Stojanović","doi":"10.1007/s00706-023-03158-0","DOIUrl":"https://doi.org/10.1007/s00706-023-03158-0","url":null,"abstract":"In this work, a sensitive and reproducible voltammetric methodology using a modified carbon paste electrode has been established for the determination of the non-steroidal anti-inflammatory drug ibuprofen. MWCNTs-supported Ni electrocatalyst was applied as a bulk carbon paste modifier to fabricate the Ni-MWCNTs-CPE sensor, while square-wave voltammetry was utilized as an electroanalytical technique. Besides, cyclic voltammetry was used to study the electrochemical behavior of ibuprofen on the proposed sensor. Parameters of square-wave voltammetry were optimized using acetate buffer pH 4.5 as an optimal electrolyte. In addition, the sensitivity of the modified carbon paste electrode, as a sensing element, was compared to the unmodified one. Under optimized conditions, a wide linear range was obtained with LOD and LOQ values of 0.86 and 2.61 µM, and 0.13 and 0.39 µM, for bare CPE and Ni-MWCNTs-CPE, respectively. The presence of the modifier in the paste improved the sensitivity of the carbon paste electrode by almost 7 times. In addition, the newly fabricated Ni-MWCNTs-CPE sensor showed better results in terms of precision (RSD up to 2.49%). Finally, the validated voltammetric methodology was successfully applied for the determination of ibuprofen content in pharmaceutical formulations, without any complicated preliminary preparation steps, with recovery values between 94.4 and 98.1%.<h3 data-test=\"abstract-sub-heading\">Graphical abstract</h3>\u0000","PeriodicalId":19011,"journal":{"name":"Monatshefte für Chemie / Chemical Monthly","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fabrication of new Mn-based MXene structure from MnO2 for electrochemical energy storage applications 利用二氧化锰制备新型锰基 MXene 结构，用于电化学储能应用

Monatshefte für Chemie / Chemical Monthly Pub Date : 2024-02-16 DOI: 10.1007/s00706-024-03173-9

Mostafa S. Eraky, Mohamed El-Sadek, Atef Y. Shenouda, Moustafa M. S. Sanad

{"title":"Fabrication of new Mn-based MXene structure from MnO2 for electrochemical energy storage applications","authors":"Mostafa S. Eraky, Mohamed El-Sadek, Atef Y. Shenouda, Moustafa M. S. Sanad","doi":"10.1007/s00706-024-03173-9","DOIUrl":"https://doi.org/10.1007/s00706-024-03173-9","url":null,"abstract":"MXene compound of Mn7C3 was successfully prepared using combined mechanical, thermal, and leaching processes. A mixture of MnO2, Al, and black C with stoichiometric ratios 3:5:2 was mechanically activated in the ball mill for 5 h. Thermal treatment at 1000 °C was applied to this mixture. Magnetic separation was used to separate Mn3AlC2 from Al2O3. After that, Al was leached from Mn3AlC2 using 15% HF. SEM investigation indicated the formation of Mxene (Mn7C3) particles as aligned sheet-like structure and particle size distribution range of 110–145 nm. The obtained MXene compounds were used as an active material vs. lithium metal and assembled in a coin cell. The electrochemical assessment of this cell was carried out using galvanostatic cycling, electrochemical impedance spectroscopy, and cyclic voltammetry techniques. MXene (Mn7C3) cell showed better performance with charge capacity by preserving about 150 mAh g−1 after 100 cycles. The coulombic efficiency of the cell is approaching 99.2% after long cycles.<h3 data-test=\"abstract-sub-heading\">Graphical abstract</h3>\u0000","PeriodicalId":19011,"journal":{"name":"Monatshefte für Chemie / Chemical Monthly","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synthesis and characterization of pyrrole-based group 4 PNP pincer complexes 基于吡咯的第 4 组 PNP 钳子复合物的合成与表征

Monatshefte für Chemie / Chemical Monthly Pub Date : 2024-02-09 DOI: 10.1007/s00706-024-03171-x

Gerald Tomsu, Berthold Stöger, Karl Kirchner

{"title":"Synthesis and characterization of pyrrole-based group 4 PNP pincer complexes","authors":"Gerald Tomsu, Berthold Stöger, Karl Kirchner","doi":"10.1007/s00706-024-03171-x","DOIUrl":"https://doi.org/10.1007/s00706-024-03171-x","url":null,"abstract":"The synthesis, characterization, and reactivity of several group 4 metal complexes featuring a central anionic pyrrole moiety connected via CH2 linkers to two phosphine donors is described. Treatment of [P(NH)P-iPr] with [MCl4(THF)2] (M = Zr, Hf) in the presence of base yields the dimeric complexes [M(PNPiPr)(μ-Cl)(Cl)2]2 featuring two bridging chloride ligands. These complexes react with sodium cyclopentadienyl and SiMe3I to give the mononuclear complexes [M(PNPiPr)(η5-Cp)(Cl)2] and [M(PNPiPr)(I)3], respectively. The latter react with MeMgBr to form the trialkyl complexes [M(PNPiPr)(Me)3]. Upon treatment of [Ti(NMe2)4] with [P(NH)P-iPr] a complex with the general formula [Ti(PNPiPr)(NMe2)3] is obtained. DFT calculations revealed that the most stable species is [Ti(κ1N- PNPiPr)(NMe2)3] featuring a κ1N-bound PNP ligand. When [P(NH)P-iPr] is reacted with [Ti(NMe2)4] in CH2Cl2 complex [Ti(PNPiPr)(Cl)2(NMe2)] is formed. Treatment of a solution of [P(NH)P-iPr] and [Zr(NMe2)4] with SiMe3Br affords the anionic seven-coordinate tetrabromo complex [Zr(PNPiPr)(Br)4][H2NMe2]. The corresponding hafnium complex [Hf(PNPiPr)(Br)4][H2NEt2] is obtained in similar fashion by utilizing [Hf(NEt2)4] as metal precursor. All complexes are characterized by means of NMR spectroscopy. Representative complexes were also characterized by X-ray crystallography.<h3 data-test=\"abstract-sub-heading\">Graphical abstract</h3>\u0000","PeriodicalId":19011,"journal":{"name":"Monatshefte für Chemie / Chemical Monthly","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Review of electrochemical impedance spectroscopy methods for lithium-ion battery diagnostics and their limitations 回顾用于锂离子电池诊断的电化学阻抗谱方法及其局限性

Monatshefte für Chemie / Chemical Monthly Pub Date : 2024-02-06 DOI: 10.1007/s00706-023-03165-1

Kateřina Nováková, Václav Papež, Jindřich Sadil, Václav Knap

引用次数: 0

Electrochemical study comparing liquid and gel electrolytes for lithium-ion batteries based on LiTDI or LiPF6 比较基于 LiTDI 或 LiPF6 的锂离子电池的液态和凝胶电解质的电化学研究

Monatshefte für Chemie / Chemical Monthly Pub Date : 2024-02-06 DOI: 10.1007/s00706-023-03166-0

Marta Kasprzyk, Andrzej Kulka, Anna Plewa, Katarzyna Walczak

{"title":"Electrochemical study comparing liquid and gel electrolytes for lithium-ion batteries based on LiTDI or LiPF6","authors":"Marta Kasprzyk, Andrzej Kulka, Anna Plewa, Katarzyna Walczak","doi":"10.1007/s00706-023-03166-0","DOIUrl":"https://doi.org/10.1007/s00706-023-03166-0","url":null,"abstract":"Liquid and gel electrolytes based on common commercial and recently commercialized salts for application in lithium-ion (Li-ion) batteries are presented herein. Various solvent mixtures and electrolytes based on them are presented. Selected organic carbonates’ mixtures are chosen as the base for these electrolytes. LiTDI (lithium 4,5-dicyano-2-(trifluoromethyl)-imidazolide) and LiPF6 (lithium hexafluorophosphate) are chosen to compare the behavior and the electrochemical properties of the investigated systems. The limited optimizations of electrolytes are presented for LiTDI salt. Results for LiPF6 electrolytes are presented as a benchmark. The detailed comparison of lithium transference numbers is presented. All liquid electrolytes present quite high values of conductivity at room temperature and in some cases reach above 6 mS cm−1 for LiTDI solutions. The base for gel electrolytes is PVdF-HFP co-polymer (poly(vinylidene difluoride-co-hexafluoropropylene)). The conductivity of gel electrolytes exceeds 1 mS cm−1 in case of the LiTDI system. All presented electrolytes show relatively high stability vs. Li/Li+, up to 4.7 V in both liquid and gel systems.<h3 data-test=\"abstract-sub-heading\">Graphical abstract</h3>\u0000","PeriodicalId":19011,"journal":{"name":"Monatshefte für Chemie / Chemical Monthly","volume":"51 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

New voltammetric sensing technique for determination of paracetamol by l-phenylalanine based carbon paste electrode 利用基于苯丙氨酸的碳糊电极测定扑热息痛的新型伏安传感技术

Monatshefte für Chemie / Chemical Monthly Pub Date : 2024-02-05 DOI: 10.1007/s00706-024-03172-w

{"title":"New voltammetric sensing technique for determination of paracetamol by l-phenylalanine based carbon paste electrode","authors":"","doi":"10.1007/s00706-024-03172-w","DOIUrl":"https://doi.org/10.1007/s00706-024-03172-w","url":null,"abstract":"<h3>Abstract</h3> In this work, the carbon paste electrode was electro-polymerized using l-phenylalanine in 0.2 M phosphate buffer solution of pH 8.0. This l-phenylalanine modified carbon paste electrode (PLPAMCPE) was used for the study of paracetamol (PCL). The modified electrode was characterized by cyclic voltammetry, differential pulse voltammetry (DPV), scanning electron microscopy, and electrochemical impedance spectroscopy. The PLPAMCPE showed an excellent current response towards the oxidation of PCL. During the pH study ranging from 5.0 to 8.0 pH, pH 6.0 showed high peak current hence considered as the optimum pH. The scan rate study showed that the reaction was adsorption-controlled reaction. Further study i.e., by varying concentration of PCL in the linear range of 1.2 µM to 12 µM, the current increases linearly. The limit of quantification of 18.2 μM and the limit of detection of 5.4 μM was obtained for the DPV method. The study also showed that the presence of different metal ions did not hinder the PCL analysis. The developed electrode showed good repeatability, stability, and reproducibility. Simultaneous study of PCL with dopamine shows good selectivity for PCL. This method is desirable due to its quickness, low cost, ease of handling, and its applicability to real sample. <h3>Graphical abstract</h3> <img alt=\"\" src=\"https://static-content.springer.com/image/MediaObjects/706_2024_3172_Figa_HTML.png\"/> ","PeriodicalId":19011,"journal":{"name":"Monatshefte für Chemie / Chemical Monthly","volume":"280 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

New route to a pyrazoline scaffold featuring original substitutions and its crystal structure 以原始取代为特色的吡唑啉支架新路线及其晶体结构

Monatshefte für Chemie / Chemical Monthly Pub Date : 2024-02-01 DOI: 10.1007/s00706-023-03169-x

Nicolas Jean-Bart, Guy Lippens, Emmanuel Gras

引用次数: 0

Synthesis of Hantzsch poly-substituted pyridines containing adamantyl moiety 含金刚烷基的汉茨多取代吡啶的合成

Monatshefte für Chemie / Chemical Monthly Pub Date : 2024-02-01 DOI: 10.1007/s00706-023-03164-2

Mina Abkar Aras, Adeleh Moshtaghi Zonouz

引用次数: 0