Lima I.V.^*, Midio A.F.^**

^* Instituto Medico Legal de S.Paulo, Rua Teodoro Sampalo 151, S.P., S.Paulo, Brazil
^** Toxicology-College of Pharmaceutical Sciences, University of S.Paulo, Av. Lineu Prestes, 580 - 05508-900, S.P. S.Paulo, Brazil

Problems related to blood contamination by other "post mortem" fluids in non decomposed bodies (NDB) and the putrefactive ethanol production in decomposed bodies (DB) make the interpretation of medicolegal blood alcohol levels a very difficult task. So, the aim of this paper is to propose the utilization of vitreous humor (VH) as an alternative and complementary biological fluid in the inequivocal determination of ethanol for forensic purposes. Alcohol was determined in both VH and blood (collected from heart and/or thoracic cavity) from 51 NDB end 30 DB. A simple headspace gas-chromatographic method was used. Ethanol distribution ratios between blood and VH were calculated. Vitreous humor correlates well with blood with a coeffcient (r²) of 0.844 for a confidence interval (a=0.05) of 1.030-1.167. Fifteen cases of endogenous alcohol were found in the 30 DB analysed. According to the results obtained it was possible to conclude that body samples collected from thoraxic cavity are not reliable for alcohol determination; vitreous humor is a complementary biological fluid when heart blood samples are not present ; vitreous humor is extremely important in determining the origin of ethanol detected in decomposed bodies.