Abstract
•Analytical method for analyzing ethanol biomarkers in postmortem fluids reported.•The first study to discuss the problem of ethanol postmortem in Saudi Arabia.•592 autopsy blood samples were tested to assess the applicability of this method.•The presence of ethanol biomarkers reliably indicates antemortem ethanol ingestion.•Some cases that were negative for ethanol in blood were positive for its biomarkers.
In Saudi Arabia, alcohol consumption is prohibited by law, but interpreting postmortem ethanol can be complicated by its postmortem production. This study developed and validated a method using headspace gas chromatography with flame ionization detection and liquid chromatography tandem mass spectroscopy to detect ethanol and its polar metabolites (ethyl glucuronide [EtG] and ethyl sulfate [EtS]) in postmortem blood and urine specimens, respectively. All calibration curves were linear with coefficients of determination greater than 0.999. The limits of detection ranged 4.5–5.0mg/dL for ethanol and 0.05–0.06mg/L for EtG and EtS. The limits of quantification were 10.0mg/dL for ethanol and 0.075mg/L for EtG and EtS. Within-run precision was less than 11% for all analytes of interest. Matrix effects for EtG and EtS ranged 3–47%. After excluding matrix effects, analytical recoveries ranged 72–100%. This validated method was then used for routine postmortem forensic toxicology analyses in 592 routine postmortem cases to distinguish between antemortem ethanol consumption and its postmortem microbial formation. Among them, 98 blood samples (17%) were positive for ethanol or its polar metabolites. Thirty-two of these cases (33%) were positive for EtG and EtS and therefore due to antemortem ethanol consumption. The remaining 66 (67%) cases were negative for both EtG and EtS and therefore due to postmortem ethanol synthesis. Because this is the first study to report the problem of alcohol consumption in Saudi Arabia, further studies are essential for validating these findings.