Sensitivity enhancement for 13C-1H 2D J-resolved NMR using a recycled-flow method

Ha, Steven T. K.; Lee, Robert W. K.; Wilkins, Charles L.

doi:10.1016/0022-2364(87)90009-6

Cited by 4 publications

(1 citation statement)

References 7 publications

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“…For mass-limited samples, it is necessary to decrease the total sample volume that is used; therefore, we currently investigate the use of a recycled-flow 50 system using a micropump. For example, a HMQC experiment on menthol accumulating 512 scans and 128 t 1 increments, such as shown in Figure 5b, could be performed in recycled-flow at a flow rate of 15 μL/min, taking into account a T 1 of 30 s. When the time between measurement on the same part of the sample is set to T 1 , the loop would need to contain approximately 7.5 μL, which corresponds to an amount of 15 μmol of menthol in our experiment.…”

Section: Resultsmentioning

confidence: 99%

Continuous Flow ¹H and ¹³C NMR Spectroscopy in Microfluidic Stripline NMR Chips

et al. 2017

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Microfluidic stripline NMR technology not only allows for NMR experiments to be performed on small sample volumes in the submicroliter range, but also experiments can easily be performed in continuous flow because of the stripline’s favorable geometry. In this study we demonstrate the possibility of dual-channel operation of a microfluidic stripline NMR setup showing one- and two-dimensional 1H, 13C and heteronuclear NMR experiments under continuous flow. We performed experiments on ethyl crotonate and menthol, using three different types of NMR chips aiming for straightforward microfluidic connectivity. The detection volumes are approximately 150 and 250 nL, while flow rates ranging from 0.5 μL/min to 15 μL/min have been employed. We show that in continuous flow the pulse delay is determined by the replenishment time of the detector volume, if the sample trajectory in the magnet toward NMR detector is long enough to polarize the spin systems. This can considerably speed up quantitative measurement of samples needing signal averaging. So it can be beneficial to perform continuous flow measurements in this setup for analysis of, e.g., reactive, unstable, or mass-limited compounds.

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Section: Resultsmentioning

confidence: 99%

Continuous Flow ¹H and ¹³C NMR Spectroscopy in Microfluidic Stripline NMR Chips

et al. 2017

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Nuclear magnetic resonance spectroscopy

Rabenstein¹,

Guo²

1988

Anal. Chem.

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Analysis of antimycin A by reversed-phase liquid chromatography/nuclear magnetic resonance spectrometry

Ha¹,

Wilkins²,

Abidi³

1989

Anal. Chem.

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A mixture of closely related streptomyces fermentation products, antimycin A, is separated, and the components are identified by using reversed-phase high-performance liquid chromatography with directly linked 400-MHz proton nuclear magnetic resonance detection. Analyses of mixtures of three amino acids, alanine, glycine, and valine, are used to determine optimal measurement conditions. Sensitivity increases of as much as a factor of 3 are achieved, at the expense of some loss in chromatographic resolution, by use of an 80-microL NMR cell, instead of a smaller 14-microL cell. Analysis of the antimycin A mixture, using the optimal analytical high-performance liquid chromatography/nuclear magnetic resonance conditions, reveals it to consist of at least 10 closely related components.

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Sensitivity enhancement for 13C-1H 2D J-resolved NMR using a recycled-flow method

Cited by 4 publications

References 7 publications

Continuous Flow ¹H and ¹³C NMR Spectroscopy in Microfluidic Stripline NMR Chips

Continuous Flow ¹H and ¹³C NMR Spectroscopy in Microfluidic Stripline NMR Chips

Nuclear magnetic resonance spectroscopy

Analysis of antimycin A by reversed-phase liquid chromatography/nuclear magnetic resonance spectrometry

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Sensitivity enhancement for 13C-1H 2D J-resolved NMR using a recycled-flow method

Cited by 4 publications

References 7 publications

Continuous Flow 1H and 13C NMR Spectroscopy in Microfluidic Stripline NMR Chips

Continuous Flow 1H and 13C NMR Spectroscopy in Microfluidic Stripline NMR Chips

Nuclear magnetic resonance spectroscopy

Analysis of antimycin A by reversed-phase liquid chromatography/nuclear magnetic resonance spectrometry

Contact Info

Product

Resources

About

Continuous Flow ¹H and ¹³C NMR Spectroscopy in Microfluidic Stripline NMR Chips

Continuous Flow ¹H and ¹³C NMR Spectroscopy in Microfluidic Stripline NMR Chips