Determination of postmortem blood vitreous humour ethanol levels and importance in forensic medicine

One of the most frequent studies in forensic toxicology laboratories is correct and reliable ethanol determination in body fluids. Blood is the most frequent sample used in these studied. Blood samples have risks of contamination and also may affected by endogenous alcohol production. Vitreous humour is more reliable sample in burned, severely injured or putrefied corpses. This procedure can be used especially on plane crash, industrial accident, trauma and fire cases. Generally vitreous humour is chemically stable. Routine application of vitreous humour analysis is necessary to provide a reliable ethanol level in putrefied corpses because of its anatomic isolation. Many studies have been published in determination of the correlation between alcohol levels in the blood and vitreous humour. In this study, ethanol levels are analysed in 87 blood samples, (obtained from femoral veins of suicidal, accidental and homicidal oriented medico-legal death cases), with the high probability of alcohol intakes detected by gas chromatography / headspace device (flame ionisation detector, FID). The samples were collected from the autopsy cases that performed at The Morgue Department, Council of Forensic Medicine Adana Group Administration, in between the dates January 2003 and June 2004. We have studied the vitreous humour alcohol levels in positive blood alcohol level cases. Therefore the transformation formula was calculated. The cases with positive blood alcohol are classified according to their ages ( 51% in 21-40 years, 39% in 41 years and over, 10% in 15-20 years of age), origins ( accident 42%, homicide 35%, suicide 23% ) and genders ( 84% male, 16% female ) and the results are discussed. Positive postmortem blood and vitreous humour alcohol levels were statistically analysed by simple linear regression and mean transformation factor was calculated as 0.803. Therefore "Blood Alcohol Concentration (BAC) = 0.803 X Vitreous Humour Alcohol Concentration (VHAC)", (r = 0.776) formula was found out. So that close correlation between vitreous humour alcohol concentrations and blood alcohol concentrations is demonstrated in our study with similar studies. Also these results demonstrate our regional data for the first time. Key Words: Forensic Toxicology, Ethanol, Vitreous Humour, Gas Chromotography, Postmortem Blood.