Preanalytical factors influencing the results of ethanol analysis in postmortem specimens.

Excessive drinking and drunkenness are underlying factors in many fatal accidents, which make the quantitative determination of ethanol in postmortem (PM) specimens an essential part of all unnatural death investigations. The same analytical methods are used to determine ethanol in blood taken from living and deceased persons although the interpretation of the results is more complicated in medical examiner cases owing to various preanalytical factors. The biggest problem is that under anaerobic conditions ethanol can be produced naturally in decomposed bodies by microbial activity and fermentation of blood glucose.

Comparisons of blood alcohol concentrations between initial testing and reanalysis from unopened tubes preserved with 0.25% NaF following refrigerated storage up to 3.93 years.

Few studies support the usage of <1% nominal sodium fluoride (NaF) to preserve ethanol in antemortem blood. Of these studies, several are limited by short study durations of 90 days or less, and there is limited research of authentic samples preserved with <1% NaF. In this retrospective analysis, data from initial and reanalysis testing of blood alcohol concentration (BAC) in antemortem blood collected in 6 mL gray-top tubes (providing 0.

Preanalytical Factors Influencing the Stability of Ethanol in Antemortem Blood and Urine Samples.

The quantitative analysis of ethanol in blood and other biological specimens is a commonly requested service from forensic science and toxicology laboratories worldwide. The measured blood alcohol concentration (BAC) constitutes important evidence when alcohol-related crimes are investigated, such as drunken driving or drug-related sexual assault. This review article considers the importance of various preanalytical factors that might influence changes in the ethanol concentration in blood after collection and before analysis or reanalysis after various periods of storage.

Statistical comparisons of 0.08 g/100 ml fortified blood alcohol samples from 6-ml and 10-ml gray-top tubes.

This experiment supplements the study, "Statistical comparisons of blood alcohol samples from 6-ml and 10-ml grey-top tubes". The initial study analyzed fortified samples for blood alcohol concentration (BAC) using two sizes of gray-top tubes: a 10-ml tube containing a nominal 1% sodium fluoride (NaF), a preservative, and a 6-ml tube containing 0.25% NaF, using the variables of time, storage temperature, fill volume, and concentration.

Statistical comparisons of blood alcohol samples from 6-mL and 10-mL grey-top tubes.

Historically, blood alcohol concentration (BAC) studies utilized a 1% concentration of the preservative sodium fluoride (NaF), leaving an information gap supporting usage of lower concentrations of NaF to preserve ethanol. As many forensic laboratories utilize Becton, Dickinson and Company 6-mL gray-top tubes (0.25% NaF), statistical comparisons were conducted to determine whether significant differences exist between BAC values obtained from 6-mL tubes versus 10-mL tubes (1% NaF).

Tape Lift Sampling of Chemical Threat Agents.

Commercial-off-the-shelf (COTS) materials were evaluated as surface samplers for the Department of Homeland Security Chemical Forensics Program. The program helps evidence collectors identify trace chemical residues at incident scenes. COTS items are widely available, produced in large lots, and with strict controls.