Disappearance of ethyl glucuronide during heavy putrefaction

Area of Science:

• Forensic Toxicology
• Post-mortem Analysis
• Ethanol Metabolite Studies

Background:

• Ethyl glucuronide (EtG) is a marker for ante-mortem alcohol ingestion in forensic autopsies.
• The stability of EtG during putrefaction is not well-understood, posing challenges for accurate interpretation.

Purpose of the Study:

• To investigate the potential for false negative and false positive EtG results due to degradation or formation during putrefaction.
• To assess the practical implications of EtG instability in real forensic cases.

Main Methods:

• An in vitro study examined EtG stability in blood under controlled putrefaction conditions (temperature, preservatives).
• Routine forensic autopsy cases with detected ethanol but undetectable EtG in blood were analyzed for EtG in urine.

Main Results:

• EtG demonstrated instability in blood at elevated temperatures (30/40°C) without preservatives.
• EtG remained stable in blood with potassium fluoride at room temperature, with no observed formation.
• Six of fifteen cases with negative blood EtG results were positive for EtG in urine, suggesting false negatives due to degradation.

Conclusions:

• Blood EtG analysis is valuable for determining in vivo alcohol ingestion in post-mortem cases.
• Negative blood EtG results, particularly in putrefied cases, require cautious interpretation.
• Analyzing an additional biological medium, such as urine, is recommended for confirmation.