Blood alcohol stability in postmortem blood samples.

ABSTRACT

The effect of long-term storage on alcohol stability in postmortem blood samples was investigated. Seventy-nine blood samples were used in this study. For the first time, blood alcohol concentrations were measured within 1 to 4 days after being taken at the Laboratory of Forensic Toxicology. After storage (ranging from 191 to 468 days), each sample was reanalyzed for blood alcohol concentration, and results were compared with the original analysis. Results showed good agreement between the experimental measurements. About 90% of the results lie within 95% limits, and 10% were outside. Despite these positive correlations, the results of some blood samples showed a high variation in ethanol concentration. Deviation in alcohol concentration between replicates of up to 10% (observed in 39% samples) is not acceptable as precise forensic evidence.