Related Experiment Video

Updated: Aug 11, 2026

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development
14:22

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development

Published on: April 15, 2013

Capillary gas chromatography/mass spectrometry of cholesteryl esters with negative ammonia chemical ionization

R P Evershed, L J Goad

    Biomedical & Environmental Mass Spectrometry
    |March 1, 1987
    PubMed

    More Related Videos

    A Study of the Complexation of Mercury(II) with Dicysteinyl Tetrapeptides by Electrospray Ionization Mass Spectrometry12:59

    A Study of the Complexation of Mercury(II) with Dicysteinyl Tetrapeptides by Electrospray Ionization Mass Spectrometry

    Published on: January 8, 2016

    Determination of 45 Pesticides in Avocado Varieties by the QuEChERS Method and Gas Chromatography-Tandem Mass Spectrometry05:20

    Determination of 45 Pesticides in Avocado Varieties by the QuEChERS Method and Gas Chromatography-Tandem Mass Spectrometry

    Published on: December 8, 2023

    Related Concept Videos

    Mass Spectrometry of Amines01:15

    Mass Spectrometry of Amines

    In mass spectroscopy, amines undergo fragmentation to give parent ions with odd molecule weights. This observed mass spectrum follows the nitrogen rule; a molecule with an odd number of nitrogen atoms produces a molecular ion with an odd molecular weight. Amines undergo fragmentation through α cleavage, producing nitrogen-containing cations—iminium ions—and alkyl radicals. Mass spectra of aromatic and cyclic aliphatic amines exhibit strong molecular ion peaks, but acyclic aliphatic amines show...
    Mass Spectrometry: Amine Fragmentation00:55

    Mass Spectrometry: Amine Fragmentation

    Amines can be identified using mass spectroscopy based on their characteristic fragmentation patterns. The molecular ions of amines undergo fragmentation via ⍺-cleavage. The ⍺-cleavage of the carbon-carbon bonds in amines generates an alkyl radical and resonance-stabilized nitrogen-containing cation.
    In amines, the number of nitrogen atoms affects the mass of the molecular ion, which is described by the nitrogen rule of mass spectrometry. This rule states that a compound containing a single or...
    Mass Spectrometry: Carboxylic Acid, Ester, and Amide Fragmentation01:01

    Mass Spectrometry: Carboxylic Acid, Ester, and Amide Fragmentation

    The fragmentation patterns observed for compounds such as carboxylic acids, esters, and amides in the mass spectra include ⍺-cleavage and McLafferty rearrangement. Fragmentation by ⍺-cleavage preferentially occurs at the carbon-carbon bond at the ⍺-position next to the carboxylic group to generate a neutral radical and a cation. Long chain compounds with hydrogen at their γ-carbon undergo McLafferty rearrangement to give a radical cation and a neutral alkene.
    For example, the fragmentation of...
    Gas Chromatography–Mass Spectrometry (GC–MS)01:14

    Gas Chromatography–Mass Spectrometry (GC–MS)

    Gas chromatography–mass spectrometry (GC–MS) is the combination of analytical techniques of gas chromatography and mass spectrometry in a single instrument for analyzing a mixture of compounds. The gas chromatograph separates the compounds in the mixture, and the mass spectrometer analyzes each compound separately to determine the molecular masses and molecular structures.
    A gas chromatograph consists of a long, narrow capillary column with a polysiloxane coating on the inner wall. The coating...
    Gas Chromatography: Types of Detectors-II01:19

    Gas Chromatography: Types of Detectors-II

    In gas chromatography, different detectors are employed to meet specific analytical needs. These detectors are often categorized based on their detection mechanisms and the types of compounds they are best suited to analyze. Thermal Conductivity Detectors (TCD), Flame Ionization Detectors (FID), and Electron Capture Detectors (ECD) represent common categories, each with unique operating principles and applications. However, beyond these, several other detectors are designed for more specialized...
    Ion-Exchange Chromatography01:09

    Ion-Exchange Chromatography

    Ion-exchange chromatography, or IEC, is a technique for separating ions based on their affinity for the stationary phase. The stationary phase is a cross-linked polymer resin with covalently attached ionic functional groups. The functional groups can be either positively charged (cation exchangers) or negatively charged (anion exchangers). A cation exchanger consists of a polymeric anion and active cations, while an anion exchanger is a polymeric cation with active anions. The choice of...