Preanalytical factors influencing the results of ethanol analysis in postmortem specimens.

This article focuses on the challenges and considerations in interpreting ethanol concentrations in postmortem (PM) specimens during forensic investigations of unnatural deaths. It highlights that ethanol can be produced after death by microbial fermentation, complicating the differentiation between antemortem (AM) ingestion and PM synthesis. To address this, forensic toxicology relies on analyzing peripheral blood (preferably femoral), vitreous humor (VH), urine, and other alternative specimens, all preserved with 1–2% sodium or potassium fluoride to inhibit post-sampling ethanol formation. The article recommends raising the analytical cut-off for reporting positive blood alcohol concentration (BAC) in PM samples from 0.01 to 0.02 g% to reduce false positives due to PM synthesis and suggests subtracting 0.05 g% from BAC results in decomposed bodies to better estimate AM ingestion. Additionally, biomarkers such as ethyl glucuronide (EtG), ethyl sulfate (EtS), phosphatidylethanol (PEth), and serotonin metabolites (5-HTOL/5-HIAA) can aid in distinguishing PM ethanol production from AM consumption, though none fully quantify the ingested amount. The review underscores the importance of comprehensive case information, proper specimen handling, and cautious interpretation of PM ethanol results, especially in legal contexts involving culpability and insurance claims.