Related Experiment Video
Updated: May 22, 2025

Author Spotlight: An Efficient Methodology to Confidently Differentiate and Characterize Fentanyl Analogs
Published on: November 8, 2024
High Resolution Mass Spectrometry Fragmentation Rules of Etomidate and Its Structural Analogues
Xian-Yu Fan1, Xue-Yan Zhu1, Xin Wang1
1Shanghai Key Laboratory of Forensic Medicine, Key Laboratory of Forensic Science, Ministry of Justice, Shanghai Forensic Service Platform, Academy of Forensic Science, Shanghai 200063, China.
Objectives:
To explore the characteristic fragment ions, ion abundance ratios and mass spectrometry fragmentation rules of etomidate and its structural analogues by using gas chromatography-quadrupole/orbitrap mass spectrometry (GC-Q/Orbitrap MS) and liquid chromatography-linear ion trap quadrupole-orbitrap mass spectrometry (LC-LTQ-Orbitrap MS) techniques, providing important data support for the identification and prediction of etomidate structural analogues.
Methods:
GC-Q/Orbitrap MS and LC-LTQ-Orbitrap MS were used to analyze metomidate, etomidate, isopropoxate and propoxate, to obtain their GC high resolution mass spectra and LC high resolution mass spectra.
Results:
Under the electron impact (EI) ion source mode, etomidate, metomidate and the other two analogues all produced their molecular ions and seven identical fragment ions (m/z 77.038 6, 79.054 2, 95.024 0, 105.069 9, 143.073 0, 172.099 5 and 199.086 6), among which isopropoxate and propoxate also produced characteristic fragment ions m/z 216.089 3. In the collision cell of the electrospray ionization (ESI) source mode, etomidate, metomidate and the other two analogues all produced three identical fragment ions (m/z 95.024 0, 105.069 9 and 113.034 6). Meanwhile, each substance produced one characteristic fragment ion (metomidate: m/z 127.050 2; etomidate: m/z 141.065 9; isopropoxate and propoxate: m/z 155.081 5).
Conclusions:
Common fragment ions exist among etomidate and its structural analogues, and characteristic ion fragments are generated based on the different carbon numbers of their side chains. The structure of side chains can affect the abundance ratio of each fragment ion, providing a basis for the structural identification and prediction of such compounds.
More Related Videos
10:17High-throughput and Comprehensive Drug Surveillance Using Multisegment Injection-Capillary Electrophoresis-Mass Spectrometry
Published on: April 23, 2019
09:24Standardized Identification of Compound Structure in Tibetan Medicine Using Ion Trap Mass Spectrometry and Multiple-Stage Fragmentation Analysis
Published on: March 17, 2023
Related Concept Videos
Mass Spectrometry: Carboxylic Acid, Ester, and Amide Fragmentation
For example,...
Mass Spectrometry: Amine Fragmentation
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...
Mass Spectrometry of Amines
Amines undergo fragmentation through α cleavage, producing nitrogen-containing cations—iminium ions—and alkyl radicals. Mass spectra of aromatic and cyclic aliphatic amines exhibit...
Mass Spectrometry: Molecular Fragmentation Overview
One type of fragmentation pattern is the cleavage of a single bond in the molecular ion. The cleavage leads to a radical and a cation. The cleavage can...
Mass Spectrum: Interpretation
To...
Mass Spectrometry: Long-Chain Alkane Fragmentation