NMR-based isotopic and isotopomic analysis

Akoka, Serge; Remaud, Gérald S.

doi:10.1016/j.pnmrs.2020.07.001

Cited by 40 publications

(65 citation statements)

References 86 publications

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“…1. Since f i depends on the efficiency of the polarization transfer delays that are not the same for each signal, it is therefore an apparent 13 C abundance that is measured [27]. While a very good precision (a few permil) is mandatory, trueness is not an issue.…”

Section: Figure Of Merit: What Is Measured?mentioning

confidence: 99%

“…Only in the last 12 years has a full protocol been proposed to achieve such a performance [24]. Irm- 13 C NMR was then used in various domains [25][26][27]. Recently, irm-NMR took advantage of the multi-pulse sequences available for the 13 C nucleus to improve sensitivity and/or resolution but still keep the high precision as the analytical target, as demonstrated by the analyses of 13 C position-specific isotope composition (PSIA) of triglycerides [28,29].…”

Section: Introductionmentioning

confidence: 99%

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A precise and rapid isotopomic analysis of small quantities of cholesterol at natural abundance by optimized 1H-13C 2D NMR

et al. 2021

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Cholesterol, the principal zoosterol, is a key metabolite linked to several health complications. Studies have shown its potential as a metabolic biomarker for predicting various diseases and determining food origin. However, the existing INEPT (insensitive nuclei enhanced by polarization transfer) 13 C position-specific isotope analysis method of cholesterol by NMR was not suitable for very precise analysis of small quantities due to its long acquisition time and therefore is restricted to products rich in cholesterol. In this work, a symmetric and adiabatic heteronuclear single quantum coherence (HSQC) 2D NMR sequence was developed for the high-precision (few permil) analysis of small quantities of cholesterol. Adiabatic pulses were incremented for improving precision and sensitivity. Moreover, several strategies such as the use of non-uniform sampling, linear prediction, and variable recycling time were optimized to reduce the acquisition time. The number of increments and spectral range were also adjusted. The method was developed on a system with a cryogenically cooled probe and was not tested on a room-temperature system. Our new approach allowed analyzing as low as 5 mg of cholesterol in 31 min with a long-term repeatability lower than 2‰ on the 24 non-quaternary carbon atoms of the molecule comparing to 16.2 h for the same quantity using the existing INEPT method. This result makes conceivable the isotope analysis of matrices low in cholesterol.

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Section: Figure Of Merit: What Is Measured?mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A precise and rapid isotopomic analysis of small quantities of cholesterol at natural abundance by optimized 1H-13C 2D NMR

et al. 2021

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“…As a consequence, these processes lead to the isotopic fractionation and their products are enriched with the lighter isotope which reacts faster than the heavier isotope. The small, but significant and detectable by NMR variations in the isotope composition of molecules during synthetic or metabolic transformations allows to form a unique isotope profile, which shows the history of the molecule [ 82 ].…”

Section: Nmr Techniques Used For Determination Of Authenticity Of mentioning

confidence: 99%

“…Therefore, this approach is an ideal method for the detection of drug counterfeiting and patent infringement because each process connected with the final product influences the isotopic fingerprint. More details about NMR principles and conditions for isotopic analysis are presented in reviews by Jézéquel et al [ 81 ] and Akoka et al [ 82 ].…”

Section: Nmr Techniques Used For Determination Of Authenticity Of mentioning

confidence: 99%

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The Application of NMR Spectroscopy and Chemometrics in Authentication of Spices

2021

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Spices and herbs are among the most commonly adulterated food types. This is because spices are widely used to process food. Spices not only enhance the flavor and taste of food, but they are also sources of numerous bioactive compounds that are significantly beneficial for health. The healing effects of spices are connected with their antimicrobial, anti-inflammatory and carminative properties. However, regular consumption of adulterated spices may cause fatal damage to our system because adulterants in most cases are unhealthy. For that reason, the appropriate analytical methods are necessary for quality assurance and to ensure the authenticity of spices. Spectroscopic methods are gaining interest as they are fast, require little or no sample preparation, and provide rich structural information. This review provides an overview of the application of NMR spectroscopy combined with chemometric analysis to determine the quality and adulteration of spices.

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Anisotropic One‐dimensional/Two‐dimensionalNMRin Molecular Analysis

Lesot

Gil

2023

Two‐Dimensional (2D) NMR Methods

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NMR-based isotopic and isotopomic analysis

Cited by 40 publications

References 86 publications

A precise and rapid isotopomic analysis of small quantities of cholesterol at natural abundance by optimized 1H-13C 2D NMR

A precise and rapid isotopomic analysis of small quantities of cholesterol at natural abundance by optimized 1H-13C 2D NMR

The Application of NMR Spectroscopy and Chemometrics in Authentication of Spices

Anisotropic One‐dimensional/Two‐dimensionalNMRin Molecular Analysis

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