The relationship between postmortem blood and vitreous humor was studied.

The New Mexico Department of Health's Toxicology Bureau performs drug and alcohol testing on thousands of medical examiner cases each year.The importance of multiple specimen analysis in alcohol-related death investigation is well understood, despite the fact that blood is usually the preferred specimen.Important interpretive information may be provided by quantitative alcohol determination in a variety of postmortem specimens.Blood and alcohol concentrations were compared in a number of cases.There was no alcohol detected in 27 of the cases.In 295 investigations, alcohol was found in the vitreous fluid, blood, or both.The need for multiple specimen analysis is reinforced by the analysis of the data and presentation of case studies.In 295 alcohol-positive cases, postmortem blood and alcohol concentrations were compared.In the majority of cases, the alcohol concentration exceeded the BAC.The concentrations of blood alcohol were equivalent in 5 cases.The samples that were negative were excluded from the study.In casework where the VAC > BAC, linear regression analysis indicated an R2 value of 0.958 and a VAC approximately 16% higher than the BAC.At lower BACs, the VAC/BAC ratio was more variable.femoral was the main source of blood for this set.The overall ratio ranged from 1.01 to 2.20.There were 24 cases where there was no vitreous alcohol.There was a wide range of blood alcohol concentrations among these cases.The source of blood in the BAC > VAC data set was slightly more variable than the VAC/BAC set.The blood source of the 81 cases where BAC > VAC was femoral, heart, pleural cavity, carotid, jugular, and chest blood.All analyses were done using dual-column gas chromatography with flame-ionization detection with a reporting limit of 0.01 g/100 mL in postmortem samples.The benefits of multiple specimen analysis are demonstrated in a series of case studies.Postmortem production of ethanol, rapid or unexpected death during the absorptive phase, and site- dependent differences following traumatic injury are some of the cases.There are actual case studies of isopropanol and acetone.Postmortem alcohol interpretation can be difficult in the absence of multiple specimen or adequate case history.