Science Case

Post mortem toxicology or forensic toxicology is a discipline of forensic science that is used to aid in medical or legal investigations of death, poisoning, and drug use. It focuses on the study of alcohol, drugs (licit and illicit) and poisons, including their chemical composition, preparations and identification. A toxical analysis can be performed to various specimens, such as blood, urine, stomach contents, bile, liver, hair, and vitreous humor. The types of blood samples that are typically used in post mortem analysis include the ante mortem blood, the postmortem blood, and the anatomical site blood.

A blood sample of approximately 10 mL is usually enough to detect and confirm most common toxic substances. Ante mortem blood is noted as the best possible blood and is typically collected prior the expiration of the patient. This type of blood sample is available in cases where the deceased was rushed to hospital and where blood was collected in the hospital emergency room.

Urine is another specimen collected in post mortem analysis. Urine is produced by the kidneys as a result of blood filtration. Along with other wastes, drugs and their metabolites are filtered by the kidneys and are contained in urine. Urine is stored in the bladder until voided. However, since urine is stored for a period of time before it is expelled, the presence of a drug in the urine does not necessarily mean the drug was present in the blood at the time of death. It simply means that some time prior to death the drug or poison was present in the blood.