A Practical Method for Automated Shimming with Normal Spectrometer Hardware

Barjat, Hervé; Chilvers, P B; Fetler, Bayard K; Horne, T. J.; Morris, Gareth A.

doi:10.1006/jmre.1996.1094

Cited by 32 publications

(16 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Automated z-gradient shimming was carried out using deuterium spin echoes. 23 DOSY spectra were measured using the BPPSTE sequence 1,5 and the newer one-shot sequence of Fig. 1(b).…”

Section: Methodsmentioning

confidence: 99%

A one‐shot sequence for high‐resolution diffusion‐ordered spectroscopy

Pelta

Morris

Stchedroff

et al. 2002

Magnetic Reson in Chemistry

240

256

View full text Add to dashboard Cite

Diffusion-ordered spectroscopy (DOSY) is a powerful method for the NMR analysis of mixtures such as crude synthetic products, biofluids or biological extracts. Mixtures can be analysed without the need for any physical separation, and the method requires only standard NMR pulsed field gradient hardware. Existing pulse sequences for DOSY require extensive and time-consuming phase cycling for clean results. A new sequence is reported here which allows clean spectra with good lineshapes to be obtained using as little as one transient per gradient value. Asymmetric bipolar field gradient pulse pairs are used in conjunction with extra balancing gradient pulses, selecting a unique coherence transfer pathway but minimizing eddy current effects and field-frequency lock disturbance. Using the new sequence, high-resolution proton DOSY spectra can be obtained in less than 1 min.

show abstract

“…Automated z-gradient shimming was carried out using deuterium spin echoes. 23 DOSY spectra were measured using the BPPSTE sequence 1,5 and the newer one-shot sequence of Fig. 1(b).…”

Section: Methodsmentioning

confidence: 99%

A one‐shot sequence for high‐resolution diffusion‐ordered spectroscopy

Pelta

Morris

Stchedroff

et al. 2002

Magnetic Reson in Chemistry

240

256

View full text Add to dashboard Cite

show abstract

“…(Although some older instru-system (Tecmag, Houston, TX) replacing the original Nicolet 1280 computer, but otherwise unmodified. The 1 H decouments do have a ''homospoil'' control which allows pulses on the Z shim coil, these permit mapping the Z axis only (34).) pler coil of a 20-mm broadband probe (Nalorac, Martinez, CA) was used for all measurements.…”

Section: Methodsmentioning

confidence: 99%

Projection-Reconstruction Spectroscopic Imaging forB0Field Plotting and Shimming without Pulsed Gradients

Gregory

1997

Journal of Magnetic Resonance

View full text Add to dashboard Cite

“…2. The only hardware modifications to the two instruments were the addition of automatic radiofrequency switching for convenience when using deuterium z phase profile shimming, and a change to the value of one capacitor in the homospoil duration limit circuitry of the shim current controller (6). Software for the analysis of the profile data was implemented in C within the Vnmr software package, using the approach described above with the singular value decomposition algorithm of Ref.…”

Section: Figmentioning

confidence: 99%

“…For most samples it is also sufficient to shim only along the z axis, since this is the direction along which most of the sampleto-sample variation in field homogeneity is concentrated, and the effects of field variation orthogonal to z can be efficiently minimized by sample spinning. z axis shimming using the deuterium lock signal for single axis spin echo phase mapping has been shown to be highly efficient both in systems equipped with a z axis pulsed field gradient (5,6) and in systems with only the slow ''homospoil'' facility to pulse the current through the z 1 shim coil (6).…”

mentioning

confidence: 99%