Ethanol determination in post-mortem samples: correlation between blood and vitreous humor concentration

Ethanol (ethylic alcohol) represents the most commonly used drug worldwide and often involved in clinical and forensic toxicology. Based on several reports, excessive alcohol consumption is the main contributing factor in causing traffic accidents, drownings, suicides and other crimes. For these reasons, it becomes essential to analyze the alcohol concentration during autopsy. Although blood is usually used for alcohol analysis in post-mortem cases, it could suffer alterations, putrefaction, and microbial contaminations. As an alternative to whole blood, vitreous humor has been successfully used in medico-legal studies. In this work, post-mortem specimens were analyzed for ethanol determination. The analysis of blood and vitreous humor were carried-out using Gas Chromatography-Flame Ionized Detector (GC-FID) with a total run time of 6 min. The method was validated in terms of limit of detection, limit of quantification, dynamic range, sensibility, recovery, precision, and trueness. A linear regression analysis indicated a coefficient of determination (R2) of 0.9981. The study confirmed no statistically differences between alcohol concentration in blood and vitreous humor, leading vitreous humor as an excellent matrix that could be used as an alternative to whole blood in toxicological analysis in cases where blood is not available.