Alcohol Analysis in Forensic Blood Samples

Alcohol use and abuse is commonly associated with criminal behavior and a variety of accidental injuries. Blood alcohol concentrations are a useful tool when estimating the degree of intoxication and performance impairment. Therefore, the analysis of alcohol in blood from both living and deceased persons has become routine in forensic laboratories. Before the analysis, blood samples must be collected, preserved, sealed, and transported in such a way as to maintain their security, avoid contamination, minimize loss of alcohol, and ensure that sample identity is clear. The most common laboratory technique for blood alcohol analysis is gas chromatography, which is described. It allows the identification of alcohol with a high degree of confidence. It also enables accurate measurement of blood alcohol concentrations. Blood alcohol analysis in forensic laboratories should always involve adherence to quality assurance protocols and routine quality control, preferably meeting international standards for chemical testing. As all results obtained for chemical tests have some associated uncertainty, analysts must take this into account when reporting results, particularly when the result is to be compared with a statutory limit.