Using high-performance quantitative NMR (HP-qNMR®) for certifying traceable and highly accurate purity values of organic reference materials with uncertainties &lt;0.1 %

Weber, M.; Hellriegel, Christine; Rück, Alex; Sauermoser, Robert; Wüthrich, Jürg

doi:10.1007/s00769-012-0944-9

Cited by 74 publications

(55 citation statements)

References 15 publications

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“…While MS analysis often does not detect possible isomers, the added value of NMR spectroscopy to the chemical identity allows for a high-level purity to be achieved (uncertainties <0.1% [55]). In this context, quantitative NMR (qNMR) is recommended by the metrological community as universal and powerful method to be used for purity determination of organic compounds [56,57].…”

Section: Discussionmentioning

confidence: 99%

Investigations of the Copper Peptide Hepcidin-25 by LC-MS/MS and NMR

Abbas

Vranić

Hoffmann

et al. 2018

Preprint

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Abstract:Hepcidin-25 was identified as the main iron regulator in the human body by binding to the sole ironexporter ferroportin. Studies showed that the N-terminus of hepcidin is responsible for this interaction, the same N-terminus that encompasses a small copper(II)-binding site known as ATCUN (amino terminal Cu(II)-and Ni(II)-binding) motif. Interestingly, this copper-binding property is largely ignored in most papers dealing with hepcidin-25. In this context, detailed investigations of the formed complex of hepcidin-25 with copper could reveal insights into its biological role. The present work is mainly focused on the study of the metal-bound form of hepcidin-25, which could be considered the biologically active form. The first part is devoted to the reversed-phase chromatographic separation of copper-bound and copper-free hepcidin-25, which was achieved by applying basic mobile phases containing 0.1% ammonia. Further, mass spectrometry (tandem mass spectrometry MS/MS, high resolution mass spectrometry HRMS) and nuclear magnetic resonance (NMR) spectroscopy were employed to characterize the copper-peptide. Lastly, a 3D model of hepcidin-25 with bound copper(II) is presented. The identification of metal complexes and potential isoforms and isomers, from which the latter usually are left undetected by mass spectrometry, led to the conclusion that complementary analytical methods are needed to characterize a peptide calibrant or reference material comprehensively. Quantitative nuclear magnetic resonance (qNMR), inductively-coupled plasma mass spectrometry (ICP-MS), ion-mobility spectrometry (IMS) and chiral amino acid analysis (AAA) should be considered among others.

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Section: Discussionmentioning

confidence: 99%

Investigations of the Copper Peptide Hepcidin-25 by LC-MS/MS and NMR

Abbas

Vranić

Hoffmann

et al. 2018

Preprint

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“…All the parameters for quantitative 19 F NMR analysis were optimized with reference to those for quantitative 1 H NMR analysis [5,11,12].…”

Section: F Nmr Measurement With Pfos-kmentioning

confidence: 99%

“…As it can be used not only for the purity determination of a pure material [5][6][7] but also for the concentration evaluation [8][9][10], this technique is a high-utility analytical method. Discussions of the accuracy of quantitative 1 H NMR spectroscopy in purity determination have also emerged [5,11,12]. 19 F NMR spectroscopy has similar properties to 1 H NMR spectroscopy; the two techniques have identical nuclear spin and similar resonance frequency and sensitivity.…”

Section: Introductionmentioning

confidence: 99%

A new approach for accurate quantitative determination using fluorine nuclear magnetic resonance spectroscopy

Yamazaki¹,

Saito²,

Ihara³

2017

J.Chem.Metrol.

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Abstract:A new approach for accurate quantitative determination by fluorine nuclear magnetic resonance ( 19 F NMR) spectroscopy is presented and discussed.19 F NMR spectroscopy has similar properties to 1 H NMR spectroscopy except for the wide chemical shift dispersion, which is the main difference between the two techniques. The off-resonance effect, which is caused by the chemical shift difference between the excitation pulse offset and the resonance signal position, is expected to be the most important parameter influencing the accuracy of the quantitative analysis by 19 F NMR spectroscopy. We propose a new method that reduces the influence of the off-resonance effect in 19 F NMR measurement. First, we discussed the areas of signals originating from different functional groups in a molecule. Then, we evaluated the areas of signals originating from two different reference materials (RMs). The accuracy of the ratios of two signal areas in the 19 F NMR spectrum of a molecule of Potassium perfluorooctanesulfonate was less than 1 %. We also evaluated the purity of flusulfamide and diflubenzuron as RMs, and found that the method could determine the purity to less than 1 % accuracy relative to the reference values.

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“…It was also used for accurate purity evaluation in reference material production. 5,6 In the purity determination by NMR spectroscopy, the measurement accuracy is influenced by the amount of the sample and the resolution of the balance. When only a few milligrams of sample is available, a high-resolution balance, such as an ultra-micro balance, must be used for sample weighing to achieve accurate determinations.…”

Section: Introductionmentioning

confidence: 99%

Concentration Measurement of Amino Acid in Aqueous Solution by Quantitative 1H NMR Spectroscopy with Internal Standard Method

2017

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We describe a procedure to determine concentrations of amino acid standard solutions by quantitative NMR spectroscopy using an internal standard. The measurement samples were prepared by solvent exchange to remove any intense solvent signal in the 1 H NMR spectra. The method was demonstrated on valine aqueous solutions of different concentrations. The accuracy of the measured concentrations that fell well within the range of the expanded uncertainty is also discussed. All of the results are in good agreement with the preparation values. We believe that this approach should be useful to determine the concentrations of standard solutions whose solute components are difficult to weigh because of extremely small amount or hygroscopicity.

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Using high-performance quantitative NMR (HP-qNMR®) for certifying traceable and highly accurate purity values of organic reference materials with uncertainties <0.1 %

Cited by 74 publications

References 15 publications

Investigations of the Copper Peptide Hepcidin-25 by LC-MS/MS and NMR

Investigations of the Copper Peptide Hepcidin-25 by LC-MS/MS and NMR

A new approach for accurate quantitative determination using fluorine nuclear magnetic resonance spectroscopy

Concentration Measurement of Amino Acid in Aqueous Solution by Quantitative 1H NMR Spectroscopy with Internal Standard Method

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