Related Experiment Video
Updated: May 26, 2026
14:11
Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis
Published on: March 29, 2016
A pulsed injection parahydrogen generator and techniques for quantifying enrichment.
Bibo Feng1, Aaron M Coffey, Raul D Colon
1Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN 37232-2310, United States.
Journal of Magnetic Resonance (San Diego, Calif. : 1997)
|December 23, 2011
Summary
This study introduces a new device for efficiently producing parahydrogen using pulsed injection of hydrogen gas. The system allows for adjustable production rates and accurate quantification, offering a valuable tool for parahydrogen production facilities.
Area of Science:
- Physics
- Chemistry
- Engineering
Background:
- Parahydrogen is a spin isomer of hydrogen with unique properties.
- Efficient and scalable production methods are crucial for its applications.
Purpose of the Study:
- To present a novel device for efficient parahydrogen enrichment.
- To detail the optimization, quantification, and storage kinetics of parahydrogen production.
Main Methods:
- Pulsed injection of hydrogen gas into a catalyst chamber cooled to 15-20K.
- Control of production rates via solenoid valves and a microcontroller.
- Quantification using 12 T NMR spectroscopy and exponential decay fitting.
Main Results:
- Achieved fast production rates of 0.9 standard liters per minute.
- Demonstrated systematic adjustment of production rates.
- Obtained parahydrogen enrichment quantification with an error of less than or equal to 1%.
Conclusions:
- The developed device offers efficient and adjustable parahydrogen production.
- The quantification method provides accurate measurements without external references.
- The system serves as a useful template for parahydrogen production facilities.
Related Concept Videos
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...
01:20¹³C 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...
01:19Inductively Coupled Plasma Atomic Emission Spectroscopy: Principle
Inductively coupled plasma (ICP) is the most widely used plasma source in atomic emission spectroscopy (AES), also known as Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The ICP source, or torch, consists of three concentric quartz tubes with argon gas flowing through them. A spark from a Tesla coil initiates the ionization of argon, generating a high-temperature plasma.
The ions and electrons produced interact with the fluctuating magnetic field created by a water-cooled...
The ions and electrons produced interact with the fluctuating magnetic field created by a water-cooled...
01:22Atomic Emission Spectroscopy: Instrumentation
The instrumentation of atomic emission spectrometry (AES) involves various components, including atomization devices that convert samples into gas-phase atoms and ions. There are two main types of atomization devices: continuous and discrete atomizers. Continuous atomizers, like plasmas and flames, introduce samples in a constant stream, while discrete atomizers inject individual samples using syringes or autosamplers. The most common discrete atomizer is the electrothermal atomizer.
01:15Insensitive Nuclei Enhanced by Polarization Transfer (INEPT)
Insensitive Nuclei Enhanced by Polarization Transfer (INEPT) is an advanced Nuclear Magnetic Resonance (NMR) technique specifically designed to detect and enhance the signals of low-abundance nuclei, such as carbon-13 and nitrogen-15, in small molecules. The fundamental principle behind INEPT is the transfer of polarization from a more abundant and highly polarizable nucleus, typically hydrogen-1, to the low-abundance nucleus of interest. This process effectively boosts the NMR signal of the...
01:19Inductively Coupled Plasma–Mass Spectrometry (ICP–MS): Overview
In inductively coupled plasma–mass spectrometry (ICP–MS), an inductively coupled plasma (ICP) torch is used as an atomizer and ionizer. Solid samples are dissolved and volatilized before being introduced into the high-temperature argon plasma, while solution samples are nebulized and passed through the high-temperature argon plasma. Plasma dissociates the analytes and ionizes their component atoms to form a mixture of positive ions and molecular species. The positive ions are then passed on to...