Validated Matrix Matched Quantification of Ethyl Chloride in Postmortem Biological Samples Using HS-GC-FID: Lung as...

Area of Science:

• Forensic Toxicology
• Analytical Chemistry
• Pharmacology

Background:

• Ethyl chloride (EC) is a volatile anesthetic with high abuse potential.
• Postmortem forensic characterization of EC is limited.
• Understanding EC's postmortem stability is vital for accurate toxicological analysis.

Purpose of the Study:

• To develop and validate a method for quantifying ethyl chloride in postmortem tissues.
• To determine the postmortem stability and distribution of ethyl chloride.
• To provide guidance on optimal sampling times and tissues for ethyl chloride detection.

Main Methods:

• An inhalation model using male Wistar rats exposed to ethyl chloride.
• Real-time photoionization detection (PID) monitoring during exposure.
• Matrix-matched headspace gas chromatography-flame ionization detection (HS-GC-FID) for quantification.
• Analysis of blood, lung, liver, brain, adipose, kidney, and muscle tissues at various postmortem intervals (0-12 h).

Main Results:

• A validated HS-GC-FID method demonstrated excellent linearity, low limits of detection and quantification, and high precision and recovery.
• Lung tissue exhibited the highest ethyl chloride concentrations overall.
• A significant decline in lung ethyl chloride concentrations was observed between 2 and 4 hours postmortem.
• Ethyl chloride concentrations became irregular in most tissues after 6 hours postmortem.

Conclusions:

• Early autopsy sampling (within 6 hours) is recommended for optimal ethyl chloride detection.
• Prioritizing lung tissue analysis can enhance detection sensitivity.
• The validated HS-GC-FID protocol offers a cost-effective and robust alternative to mass spectrometry for routine forensic volatile screening.