Putrefactive Ethanol
Definition
Ethanol produced post-mortem by microbial fermentation of glucose, lactate and amino acids. Can give false-positive BAC; vitreous humor is the matrix of choice to rule it out.
- Cause
- Microbial fermentation of glucose, lactate and amino acids after death
- Risk
- False-positive blood alcohol concentration
- Preferred matrix to rule out
- Vitreous humor
Common questions
Why is vitreous humor preferred over blood to rule out putrefactive ethanol?+
Vitreous humor is anatomically isolated within the eye and less accessible to microbial invasion than blood, so ethanol detected there more reliably reflects true antemortem consumption rather than postmortem fermentation.
What other markers help distinguish putrefactive ethanol from ingested alcohol?+
Comparing ethanol levels across multiple sample sites such as blood, vitreous humor and urine, and checking for other fermentation byproducts like n-propanol, can support distinguishing genuine ingestion from postmortem microbial production.
Related terms
- ADH Assay
- Alcohol dehydrogenase enzymatic assay. Ethanol plus NAD+ gives acetaldehyde plus NADH; NADH absorbance at 340 nm is proportional to ethanol concentration. Fast...
- BAC
- Blood Alcohol Concentration. Mass of ethanol per unit volume of whole blood. Indian legal cut-off is 30 mg per 100 mL (0.03...
- Fuel-Cell Breath Analyser
- Electrochemical sensor: ethanol oxidises at a platinum electrode generating a current proportional to BrAC. Specific for ethanol, used in Drager Alcotest and...
- Headspace GC-FID
- Gas chromatography with flame-ionisation detection run on the vapour above a sealed sample. The standard forensic method for methanol and ethanol in...
- IR Breath Analyser
- Infrared absorption at about 3.4 micrometres (C-H stretch) or 9.5 micrometres (C-O stretch). Specific and quantitative; used in Intoxilyzer 8000 and evidential...
- Wet-Bath Simulator
- Calibration accessory holding a 0.10 g per L aqueous ethanol solution at 34 degrees Celsius. The vapour above gives a known reference...
- Widmark Formula
- A = r × W × C, where A is total alcohol in body (g), W is body weight (kg), C is...