Postmortem alcohol

• Author: James G. Wigmore
• Pages: 125-141

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 

Postmortem Alcohol

The analysis a nd interpretation of alcohol testing postmortem is more

complicated than in blood samples collected from living subject s. Fac-

tors such as postmortem dif‌fu sion and putrefaction (partially as a result

of high postmortem blood sugar concentrations) can af‌fect the results.

Blood can be collected from a variety of areas, such as the heart, i liac

(leg) vein, or a hematoma (blood clot), rather than from just venous

blood, which is routinely collected from living persons in drinking-and-

driving cases. As well the alcohol concentration can be determined in

vitreous humor (VH), liver, bile, or muscle. Postmortem biomarkers of

alcohol ingestion can assist in determi ning whether the postmortem

blood alcohol concentration (BAC) has been af‌fected by putrefaction.

In general, the postmortem BAC is not as stable as blood collected

from living subjects for the following reason s:

• Postmortem blood is not sterile.

• Numerous bacteria and yeast s that migrate from the gut post-

mortem are present in the blood.

• Postmortem blood can have very high glucose concentration.

7.01 METHODS OF ANALYSIS

Headspace gas chromatography (GC) is the cur rent preferred method of

alcohol analysis in postmortem blood samples, as it is for antemortem

samples. It is recommended, however, that t-butanol be employed as the

internal sta ndard rather than n-propanol, which is commonly used for an-

temortem samples, as n-propanol is a putrefactive product (, ).

126  The Abridged Wigmore on Alcohol

Reference Number: 

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raphy, : –,  ( tables,  f‌igures,  references)

Reference Number: 70102

’, .., ..  , . , . ,  . . “Gas

Chromatographic Procedures for Determination of Ethanol in Post-

mortem Blood Using t-Butanol and Methyl Ethyl Ketone as Internal

Standards.” Forensic Science International, : –,  ( tables, 

f‌igures,  references)

Reference Number: 70103

, ., . ,  .. . “Evaluation of Ethanol Analy-

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 , ..,  ... . “Automated Headspace Solid-Phase

Microextraction and Capillary Gas Chromatography Analysis of Eth-

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–,  ( tables,  f‌igures,  references)

7.02 PUTREFACTION AND PRESERVATION

Postmortem blood is more prone to putrefaction and the endogenous

formation of alcohol than antemortem blood, in part due to its pot-

entially high glucose content and exposure to microorganisms (,

). The glucose can be fermented by yeasts, bacteria , and fungi

through various steps into aceta ldehyde and carbon dioxide and eventu-

ally to alcohol, as shown:

CHO →  CHCHO +  CO →  CHCHOH

Yeasts, the most ecient fermenters, can convert approximately

.g/ mL of glucose into approximately .–.g/ mL

of alcohol, whereas bacteria and fungi can produce only about .–