Article
Chemistry, Analytical
Yulia B. Monakhova, Bernd W. K. Diehl
Summary: This paper introduces a new method for quantitative nuclear magnetic resonance (qNMR) analysis, using the NMR signal of another active nuclei for calibration. The new approach can be used to determine deuteration levels in different deuterated solvents, with benefits of reduced uncertainties and sample preparation steps.
Article
Chemistry, Analytical
Qiao Lin, Chunwang Meng, Jie Liu, Fei Liu, Qinmei Zhou, Juan Liu, Cheng Peng, Liang Xiong
Summary: With the development of NMR spectrometers and probes, 2D qNMR technology has become increasingly accessible for quantitation of complex mixtures. However, the need for a long relaxation recovery time makes it difficult for 2D qNMR to achieve high quantitative accuracy and data acquisition efficiency. By using relaxation optimization and nonuniform sampling, we successfully established an optimized 2D qNMR strategy for accurate quantitation of diester-type C-19-diterpenoid alkaloids.
ANALYTICAL CHEMISTRY
(2023)
Article
Medicine, Legal
Nao Wu, Saida Danoun, Stephane Balayssac, Myriam Malet-Martino, Catherine Lamoureux, Veronique Gilard
Summary: The H-1 NMR profiles of 13 e-liquids provided by French customs were analyzed using high-field and low-field NMR, detecting synthetic cannabinoids and flavoring compounds, with successful quantitative analysis. Fluorine-19 NMR was proposed for quantification of fluorinated synthetic cannabinoids, showing potential for both qualitative and quantitative analysis in e-liquids.
FORENSIC SCIENCE INTERNATIONAL
(2021)
Article
Chemistry, Analytical
Vincent Guillou, Torsten Schoenberger
Summary: The excellent principle of quantitative NMR spectroscopy can also be used for quadrupolar nuclei, allowing for qualitative and quantitative determination of ionized drug components. External calibration method, which is highly stable, has been accredited to ISO 17025. The methods are robust, and analysis can be performed quickly and conveniently.
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
(2022)
Article
Chemistry, Analytical
Saida Danoun, Stephane Balayssac, Veronique Gilard, Robert Martino, Myriam Malet-Martino
Summary: This study proposes a new analytical methodology based on low-field NMR to evaluate the quality of berberine food supplements. The results show that the labels of these supplements are often unclear or incomplete, and only 56% of the analyzed samples actually contain the claimed quantity of berberine.
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
(2023)
Article
Biotechnology & Applied Microbiology
Thao Quyen Cao, Dongyup Hahn
Summary: This study developed a 1H quantitative nuclear magnetic resonance (qNMR) method for quantification of allantoin in yams. The method was based on the relative ratio of signals integration of allantoin to the internal standard dimethyl sulfone (DMSO2) and validated in terms of specificity, linearity, sensitivity, precision, and recovery. The method was then applied to evaluate the allantoin content in the flesh and peel extracts of four different yams cultivated in Korea.
JOURNAL OF MICROBIOLOGY AND BIOTECHNOLOGY
(2023)
Article
Chemistry, Analytical
Ana Belen Ruiz-Muelle, Paula Garcia Moreno, Ignacio Fernandez
Summary: NMR offers unique potential for selective excitation of specific nuclei and avoiding matrix effects; Quantitative N-14 qNMR spectroscopy is a robust method for determining choline in various matrices; Study of ion pairing of choline bitartrate in aqueous solution and fast, reliable quantification of choline were also provided.
Review
Biochemistry & Molecular Biology
Sofia Moco
Summary: The direct analysis of metabolic intermediates in biological samples has greatly advanced the understanding of metabolic processes. Mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy have played a key role in these advancements. NMR, originally used for elucidating molecular structures, has now been extended to the analysis of complex mixtures in biological samples, known as NMR-based metabolomics. NMR is also powerful in other areas of small molecule biochemistry, including quantification of metabolites, determining metabolic fate, uncovering new metabolic pathways, studying metabolite-protein interactions, and understanding metabolic regulation and pharmacological effects. The development of computational tools and resources has contributed to a more detailed understanding of systems biochemistry.
FRONTIERS IN MOLECULAR BIOSCIENCES
(2022)
Article
Chemistry, Physical
Hideshi Maki, Keita Baba, Yongjin Oh, Minoru Mizuhata
Summary: The Cl-35 qNMR method was successfully established, showing high linearity in calibration curves and detecting various Al hydrolysis products. The study revealed the concentration changes of K-Al-13 and the efficient coagulation mechanism for the model sludge with highly charged K-Al-13. The aggregation rate of the PACS-0.15 model sludge was influenced by the presence of SO42- ions, affecting the formation of large flocs.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Chemistry, Analytical
Ana Belen Ruiz-Muelle, Concepcion Diaz Navarro, Ignacio Fernandez
Summary: A qQNMR methodology using nitrogen-14 as the quadrupolar nucleus has been introduced for the determination and quantification of L-carnitine in food supplements. The method was validated at seven concentration levels with high precision and robustness, showing low limits of detection and quantification. The absence of matrix effect is a notable feature of this method.
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
(2022)
Article
Chemistry, Analytical
Gennady Khirich
Summary: Quantitative nuclear magnetic resonance (qNMR) is a powerful analytical technology that can quantify the concentration of any analyte with high accuracy, with the uncertainty influenced by various factors such as spectroscopic parameters, data processing, signal-to-noise ratios, and signal quantification methods. The Monte Carlo (MC) method provides a way to calculate the contributions to qNMR measurement uncertainty and allows for a general quantitative assessment without the need for spectral replicates or reference to molecular structures.
ANALYTICAL CHEMISTRY
(2021)
Article
Chemistry, Analytical
Gabriel Giancaspro, Kristie M. Adams, Sitaram Bhavaraju, Charlotte Corbett, Bernd Diehl, J. Christoph Freudenberger, Klaus Fritsch, Krish Krishnamurthy, Pekka Laatikainen, Gustavo Martos, Toru Miura, Joo-Won Nam, Matthias Niemitz, Yuzo Nishizaki, Naoki Sugimoto, Markus Obkircher, Rasika Phansalkar, G. Joseph Ray, Takeshi Saito, Dan Sorensen, Aaron Urbas, Jose G. Napolitano, Fatkhulla Tadjimukhamedov, Anton Bzhelyansky, Yang Liu, Guido F. Pauli
Summary: The goal of the qNMR Summit is to review the status quo and recent developments in qNMR research and applications, providing a platform for practitioners to discuss potential applications and collaborations. The Summit focuses on standardization of qNMR methodology, metrological and pharmacopeial utility, with presentations on methodology in the pharmaceutical industry and advanced quantitation algorithms.
ANALYTICAL CHEMISTRY
(2021)
Article
Chemistry, Analytical
Anca Frinculescu, Alexander F. G. Maier, Trevor Shine, John Ramsey, Juan F. Araneda, Susanne D. Riegel, Nunzianda Frascione, Vincenzo Abbate
Summary: This study describes a method validation for quantifying MDMA in tablets based on the UNODC guideline for qNMR analysis. The method showed good specificity and selectivity, with results within the recommended criteria. The study also identified within-batch variation in MDMA content and highlighted the importance of ongoing trend monitoring and prevention intervention.
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
(2022)
Article
Biochemistry & Molecular Biology
Yue-Chiun Li, Chia-Hung Wu, Thi Ha Le, Qingjun Yuan, Luqi Huang, Guo-Fen Chen, Mei-Lin Yang, Sio-Hong Lam, Hsin-Yi Hung, Handong Sun, Yi-Hung Wu, Ping-Chung Kuo, Tian-Shung Wu
Summary: A specific H-1-NMR method has been modified to quantify ephedrine alkaloids. Benzene was identified as the better extraction solvent to eliminate impurities. The locations of ephedrine alkaloids were confirmed using 2D NMR, and the concentrations of ephedrine and pseudoephedrine varied greatly among different species and collection locations of Ephedra plants.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Applied
Raphael Convertini, Claus Patz, Keshav Kumar, Bianca May, Wilfried Andlauer, Ralf Schweiggert
Summary: This study optimized a method originally used for wine analysis for quantification of methanol in apple-based beverages. By comparing it with other methods, the optimized method was found to provide reliable results. The optimized qNMR method can be considered as an alternative approach for methanol quantification.
