Related Experiment Video
Updated: May 21, 2026
12:47
Nuclear Magnetic Resonance Spectroscopy for the Identification of Multiple Phosphorylations of Intrinsically Disordered Proteins
Published on: December 27, 2016
Communication: Phase incremented echo train acquisition in NMR spectroscopy
Jay H Baltisberger1, Brennan J Walder, Eric G Keeler
1Division of Natural Science, Mathematics, and Nursing, Berea College, Berea, Kentucky 40403, USA.
The Journal of Chemical Physics
|June 16, 2012
Summary
We introduce phase incremented echo train acquisition (PIETA), an improved method for magnetic resonance spectroscopy. PIETA reduces artifacts common in Carr-Purcell-Meiboom-Gill (CPMG) acquisition and enables faster measurements.
Area of Science:
- Magnetic Resonance Spectroscopy
- Nuclear Magnetic Resonance
Background:
- Conventional Carr-Purcell-Meiboom-Gill (CPMG) acquisition in magnetic resonance spectroscopy can introduce artifacts.
- Echo Train Acquisition (ETA) enhances experiments but typically increases dimensionality by one (N+1).
Purpose of the Study:
- To present a modified echo train acquisition technique, phase incremented echo train acquisition (PIETA).
- To demonstrate PIETA's ability to mitigate artifacts and improve spectral data quality.
- To enable efficient measurements of transverse relaxation and J-couplings.
Main Methods:
- Developed PIETA by incrementing the phase of specific pulses, creating an N+2 dimensional experiment.
- Utilized Fourier transform on the phase increment dimension to separate signal pathways.
- Applied PIETA to experiments with phase-modulated signals post-mixing pulse.
Main Results:
- PIETA effectively eliminates artifacts often seen with CPMG acquisition.
- Achieved single-scan measurements of transverse relaxation and J-couplings.
- Demonstrated PIETA's compatibility with phase-modulated signals.
Conclusions:
- PIETA offers a robust and generalizable improvement over conventional ETA and CPMG methods.
- This technique simplifies data processing and enhances artifact removal in NMR spectroscopy.
- PIETA expands the applicability of echo train acquisition in complex NMR experiments.
More Related Videos
Related Concept Videos
01:17NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences
A pulse is a short burst of radio waves distributed over a range of frequencies that simultaneously excites all the nuclei in the sample. Upon passing a radio frequency pulse along the x-axis, the nuclei absorb energy corresponding to their Larmor frequencies and achieve resonance. This shifts the net magnetization vector from the z-axis toward the transverse plane. This angle of rotation of the magnetization vector, or the flip angle, is proportional to the duration and intensity of the pulse.
01:12Double Resonance Techniques: Overview
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
01:20¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
01:10Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule
In the AX proton spin system, proton A can sense the two spin states of a coupled proton X, resulting in a doublet NMR signal with two peaks of equal (1:1) intensity. When proton A is coupled to two equivalent protons (AX2 spin system), the spin states of each X can be aligned with or against the external field, creating three possible scenarios. This results in a 1:2:1 triplet signal, where the central peak corresponds to the chemical shift of A and is twice as large or intense as the others.
01:12Two-Dimensional (2D) NMR: Overview
The 1D NMR spectrum of large and complex molecules like natural products has complicated splitting patterns and overlapping signals, which can be easily interpreted using 2-dimensional (2D) NMR. Unlike 1D NMR, 2D NMR has two frequency axes that provide the coupling information between the nucleus A and nucleus B in a molecule. The process from which 2D spectra are obtained has four steps.
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse.
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse.