Magnetic Resonance in Chemistry最新文献

Enhancing Forensic Laboratories Through University Collaboration: Obtaining Conclusive Reports and Reference Materials via NMR. 通过大学合作加强法医实验室：通过 NMR 获取结论性报告和参考材料。

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-11-28 DOI: 10.1002/mrc.5497

Luciano Chaves Arantes, Dâmaris Silveira, Gabriel Magno Sousa de Azerêdo, Omar Enrique Estrada Semprun, Aline Lima de Oliveira, Luiz Eduardo Celino Benedito, Luciano Morais Lião, Gerlon de Almeida Ribeiro Oliveira

{"title":"Enhancing Forensic Laboratories Through University Collaboration: Obtaining Conclusive Reports and Reference Materials via NMR.","authors":"Luciano Chaves Arantes, Dâmaris Silveira, Gabriel Magno Sousa de Azerêdo, Omar Enrique Estrada Semprun, Aline Lima de Oliveira, Luiz Eduardo Celino Benedito, Luciano Morais Lião, Gerlon de Almeida Ribeiro Oliveira","doi":"10.1002/mrc.5497","DOIUrl":"https://doi.org/10.1002/mrc.5497","url":null,"abstract":"Forensic laboratories play a pivotal role in identifying and quantifying drugs in police seizures, often using spectroscopic techniques in combination with chromatographic methods that rely on chemical reference substances (CRS). The demand for a wide variety of CRS is critical, not only for common drugs like cocaine but also for the rapidly increasing number of new psychoactive substances (NPS), which emerge weekly. However, acquiring CRS is costly and bureaucratic because of the restricted circulation of these substances. Nuclear magnetic resonance (NMR) offers a viable alternative to identifying and quantifying substances without the need for specific CRS for each analyte. Although NMR equipment is commonly available at universities, it is typically absent from police laboratories because of its high initial cost. This work highlights a successful partnership between a forensic laboratory and university-based NMR facilities as a cost-effective strategy for obtaining CRS. A case study involving four substances-cocaine, two recently scheduled NPS, metonitazene and dipentylone, and ADB-5'Br-BUTINACA-demonstrates the effectiveness of this collaboration. This partnership allowed the generation of conclusive reports for seized substances, providing early warnings about NPS and helping to prevent potential outbreaks and public health crises. Additionally, the strategy facilitated the acquisition of expensive CRS from samples that would otherwise be destroyed, at a reduced cost and within a shorter timeframe. Furthermore, this partnership enhances student training in advanced instrumental analysis and research, showcasing the benefits of collaboration between forensic and academic institutions.","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142739832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Structural Elucidation and NMR Spectral Assignments of New Diphenyl Ether Derivatives From Liuweizhiji Gegen-Sangshen Oral Liquid. 六味地黄口服液中新的二苯醚衍生物的结构阐释和核磁共振谱定位

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-11-18 DOI: 10.1002/mrc.5496

Jinghao Cui, Xin Zhou, Baorui Teng, Dan Zhang, Xiujuan Fu, Siwei Chen, Sijing Liu, Zhi Li, Hui Lei

引用次数: 0

Liquid-Phase NMR of Humic and Fulvic Acids. 腐殖酸和富味酸的液相核磁共振。

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-11-16 DOI: 10.1002/mrc.5493

Leonid B Krivdin

{"title":"Liquid-Phase NMR of Humic and Fulvic Acids.","authors":"Leonid B Krivdin","doi":"10.1002/mrc.5493","DOIUrl":"https://doi.org/10.1002/mrc.5493","url":null,"abstract":"Present review focuses on the most recent advances in the NMR of the coal-derived humic and fulvic acids, covering exclusively the results of the liquid-phase NMR and leaving apart an overwhelming amount of publications dealing with the solid-state NMR investigations in this field (the latter are comprehensively reviewed elsewhere). Owing to the complexity of humic and fulvic acids together with other coal-derived products, their 1H and 13C NMR spectra consist of a number of overlapping signals belonging to different hydrocarbon types. Comprehensive studies of humic and fulvic acids by means of NMR revealed characteristic functional groups of their composition together with spectral regions in which they resonate. Quantitative 1H and 13C NMR spectra characterize aromatic and saturated carbons spread over many structural moieties, which provides a solid guideline into molecular structure of humic and fulvic acids together with parent coal-derived products. Nowadays, quantitative 13C NMR measurements yield information about a variety of structural parameters such as functional group distribution, aromaticity, degree of condensation of aromatic rings, and medium chain lengths together with many other more specific parameters. The structural NMR studies of the coal-derived products are developing on a background of a marked progress in experimental and computational NMR. Discussed in the present review are the most recent advances in the liquid-state NMR studies of the coal-derived humic and fulvic acids together with their processing products.","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142644446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Two New Alkaloids of the Endophytic Fungus Rhizopus oryzae From Atractylodes macrocephala Koidz. 白术内生真菌 Rhizopus oryzae 的两种新生物碱 Koidz.

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-11-15 DOI: 10.1002/mrc.5495

Yue Meicen, Lei Hui, Teng Baorui, Fu Xiujuan, Chen Siwei, Wang Zan, Zhang Dan, Luo Yu

引用次数: 0

HRMAS NMR for Studying Solvent-Induced Mobility of Polymer Chains and Metallocene Migration Into Low-Density Polyethylene (LDPE). HRMAS NMR 用于研究溶剂诱导的聚合物链流动性以及茂金属向低密度聚乙烯 (LDPE) 的迁移。

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-11-06 DOI: 10.1002/mrc.5484

John C Hoefler, Maxwell R Kimball, Janet Blümel

{"title":"HRMAS NMR for Studying Solvent-Induced Mobility of Polymer Chains and Metallocene Migration Into Low-Density Polyethylene (LDPE).","authors":"John C Hoefler, Maxwell R Kimball, Janet Blümel","doi":"10.1002/mrc.5484","DOIUrl":"https://doi.org/10.1002/mrc.5484","url":null,"abstract":"HRMAS (high-resolution magic angle spinning) nuclear magnetic resonance (NMR) spectroscopy of low-density polyethylene (LDPE) affords 1H and 13C NMR spectra with superior resolution. For acquiring HRMAS NMR spectra, the polymer is first swollen with representative organic solvents. Then, the samples are measured with a conventional solid-state NMR spectrometer in the wideline mode or at the low spinning speed of 2 kHz. Anisotropic interactions like CSA (chemical shift anisotropy) and dipolar interactions are reduced due to the additional mobility of the polymer chains in the presence of the solvent within the polymer network. The combined effect of this mobility and MAS leads to signals with substantially reduced halfwidths as compared to classic MAS of the dry polymer. With HRMAS, all signals of the polymer become visible, and the spectra can be used for a quick and easy assessment of the polymer swelling behavior in diverse solvents. Being able to characterize polymers on the molecular level, and identifying the solvents that penetrate the polymer network best, enables the study of post-synthesis modifications of the polymers. It is demonstrated by paramagnetic HRMAS that the metallocene nickelocene (Cp2Ni) penetrates the LDPE network along with the solvent and is homogeneously dispersed in the polymer. SEM images prove that the structure of the polymer is not altered by the presence of a solvent and Cp2Ni. The impact of the paramagnetic Cp2Ni on the 1H signal halfwidth and T1 time of LDPE is studied. HRMAS allows a quick assessment of metal complexes regarding their ability to penetrate the LDPE network and therefore supports future studies of catalytic polymer degradation.","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142591104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Structural Elucidation and Complete NMR Spectral Assignments of Monascus Monacolin Analogs. Monascus Monacolin 类似物的结构阐释和完整 NMR 光谱分配。

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-11-05 DOI: 10.1002/mrc.5489

Jiachen Liu, Qingjiang Xu, Xin Wang, Ronghua Pan, Lizhong Zheng, Yonghong Zhang, Xiaoya Shang, Nan Wang

引用次数: 0

Reversibly Compressible Cross-Linked Polystyrene Gels, Compatible With Toluene-d₈ and Pyridine-d₅, for Measurement of Residual Dipolar Couplings and Residual Chemical Shift Anisotropies. 与甲苯-d8 和吡啶-d5 兼容的可逆压缩交联聚苯乙烯凝胶，用于测量残余双极耦合和残余化学位移各向异性。

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-11-04 DOI: 10.1002/mrc.5494

Franciane G Dos Santos, Daiane S Carvalho, Fernando Hallwass, Armando Navarro-Vázquez

引用次数: 0

A New qNMR Compliant Savitzky-Golay Apodization Function for Resolution Enhancement. 用于提高分辨率的新型 qNMR 兼容型 Savitzky-Golay 光晕函数

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-11-03 DOI: 10.1002/mrc.5492

Carlos Cobas, José Antonio García-Pulido, Paula Mora, Giovanni Selva, Stan Sykora

引用次数: 0

NMR Relaxometry to Monitor In Situ the Loading of Amberlite IR120 and Dowex Marathon MSC Resins With Ni²⁺ and Cu²⁺ During a Column Experiment. 核磁共振弛豫测定法用于监测 Amberlite IR120 和 Dowex Marathon MSC 树脂在色谱柱实验中对 Ni2+ 和 Cu2+ 的原位加载。

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-10-30 DOI: 10.1002/mrc.5490

Marie Bernardi, Rodrigo de Oliveira Silva, Quoc Lam Vuong, Dimitrios Sakellariou, Yves Gossuin

{"title":"NMR Relaxometry to Monitor In Situ the Loading of Amberlite IR120 and Dowex Marathon MSC Resins With Ni2+ and Cu2+ During a Column Experiment.","authors":"Marie Bernardi, Rodrigo de Oliveira Silva, Quoc Lam Vuong, Dimitrios Sakellariou, Yves Gossuin","doi":"10.1002/mrc.5490","DOIUrl":"https://doi.org/10.1002/mrc.5490","url":null,"abstract":"The removal of heavy metal ions from wastewater often necessitates the use of ion exchange resins. Current methods for assessing ion exchange efficiency are indirect and destructive. Some heavy metal ions, such as Cu2+ and Ni2+, are paramagnetic and influence the NMR relaxation times of water protons. NMR relaxometry can therefore be utilized to track the removal of these ions by ion exchange resins. In this study, we use relaxometry to monitor in situ the loading with Ni2+ and Cu2+ of Amberlite IR120 and Dowex Marathon MSC resins, with the resin column inserted into a low-field NMR device. The multiexponential transverse relaxation curves were fitted using a biexponential model. Before and during the loading of the resin, the water with the slowest relaxation corresponds to treated water (free of Ni2+ or Cu2+) flowing between the resin beads. After saturation, the slowest fraction corresponds to the untreated solution (containing Ni2+ or Cu2+) flowing between the resin beads saturated with paramagnetic ions. The evolution with time of the transverse relaxation rate and the amplitude of the slowly relaxing water fraction shows a clear transition, occurring later at the bottom of the resin bed compared with the middle and top. This is interpreted as an indication of the saturation of the studied zone with paramagnetic ions, confirmed by the quantification of Ni2+ or Cu2+ in the effluent using AES spectroscopy. This proof-of-concept study demonstrates that NMR relaxometry can be used in situ to monitor the loading of a resin bed with paramagnetic ions.","PeriodicalId":18142,"journal":{"name":"Magnetic Resonance in Chemistry","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

To Gibbs or Not to Gibbs Effect of Entropic Contribution in the NMR Calculations of Flexible and Polar Molecules—Updating the DP4+App 柔性和极性分子核磁共振计算中熵贡献的吉布斯效应（To Gibbs or Not to Gibbs Effect of Entropic Contribution in the NMR Calculations of Flexible and Polar Molecules）-更新 DP4+App.

IF 1.9 3区化学

Magnetic Resonance in Chemistry Pub Date : 2024-10-30 DOI: 10.1002/mrc.5491

Milagros Amichetti, Bruno A. Franco, María Marta Zanardi, Ariel M. Sarotti

引用次数: 0