Related Experiment Video

Updated: Jun 14, 2026

Identification and Quantification of Deranged Metabolites in Critically Ill Patients Using NMR-Based Metabolomics
11:02

Identification and Quantification of Deranged Metabolites in Critically Ill Patients Using NMR-Based Metabolomics

Published on: November 29, 2024

Quantification of molecules in (1)H-NMR metabolomics with formate as a concentration standard

Itiro Ando, Takuo Hirose, Tadashi Nemoto

    The Journal of Toxicological Sciences
    |April 8, 2010
    PubMed

    More Related Videos

    A Strategy for Sensitive, Large Scale Quantitative Metabolomics14:18

    A Strategy for Sensitive, Large Scale Quantitative Metabolomics

    Published on: May 27, 2014

    Concentration of Metabolites from Low-density Planktonic Communities for Environmental Metabolomics using Nuclear Magnetic Resonance Spectroscopy11:47

    Concentration of Metabolites from Low-density Planktonic Communities for Environmental Metabolomics using Nuclear Magnetic Resonance Spectroscopy

    Published on: April 7, 2012

    Related Concept Videos

    Mass Spectrum: Interpretation01:24

    Mass Spectrum: Interpretation

    An unknown compound can be established by identifying the molecular ion peak in the mass spectrum. The molecular ion peak is often weak or absent due to the predominance of fragmentation in high-energy electron beams. In such cases, a soft-energy electron beam can be used to scan the spectrum to enhance the intensity of the molecular ion peak. Additionally, chemical ionization, field ionization, and desorption ionization spectra are used to obtain a relatively intense molecular ion peak.To...
    High-Resolution Mass Spectrometry (HRMS)01:15

    High-Resolution Mass Spectrometry (HRMS)

    The resolution of a mass spectrometer depends on the efficiency of separating ions with different ion masses. The mass of an atom is approximated to the sum of the masses of protons and neutrons inside, considering the masses of protons and neutrons as equal. However, the masses of the proton (1.6726 × 10−24 g) and neutron (1.6749 × 10−24 g) are not truly equal. There is a minor error in the expression of atomic masses relative to the simplest atom of hydrogen. For example, the mass of helium...
    ¹H NMR Signal Integration: Overview00:58

    ¹H NMR Signal Integration: Overview

    The intensity of a signal, which can be represented by the area under the peak, depends on the number of protons contributing to that signal. The area under each peak is shown as a vertical line called an integral, with the integral value listed under it, as seen in the proton NMR spectrum of benzyl acetate. Each integral value is divided by the smallest integral value to obtain the ratio of the number of protons producing each signal. The ratio reveals the relative number of protons and not...
    2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)01:19

    2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)

    Heteronuclear single-quantum correlation spectroscopy (HSQC) is a 2D NMR technique that reveals one-bond correlations between hydrogen and a heteronucleus. The HSQC experiment is similar to the heteronuclear correlation experiment (HETCOR) but is more sensitive. In the HSQC spectrum, the proton chemical shift is plotted on the horizontal F2 axis, while the 13C chemical shift is plotted on the vertical F1 axis. The corresponding proton and 13C spectra are also shown. The HSQC contour plot does...
    Chemical Shift: Internal References and Solvent Effects01:17

    Chemical Shift: Internal References and Solvent Effects

    In an NMR sample, precise measurement of the absolute absorption frequencies of nuclei is difficult. A standard internal reference compound is added, and the frequency difference between the reference signal and sample signals is measured.
    The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...
    ¹H NMR of Conformationally Flexible Molecules: Temporal Resolution00:52

    ¹H NMR of Conformationally Flexible Molecules: Temporal Resolution

    At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...