Forensic toxicology
Armed with this contextual information and samples to examine, the forensic toxicologist is tasked with identifying the specific toxic substances[2] present, quantifying their concentrations, and assessing their likely impact on the individual involved.
[4] Postmortem toxicology involves analyzing biological specimens obtained during an autopsy to identify the impact of drugs, alcohol, and poisons.
A broad array of biological specimens, including blood, urine, gastric contents, oral fluids, hair, and tissues, may undergo analysis.
Forensic toxicologists collaborate with pathologists, medical examiners, and coroners to ascertain the cause and manner of death.
This field plays a pivotal role in shaping and implementing laws related to activities such as driving under the influence of alcohol or drugs.
Unlike a regulated dose of a drug, which may contain grams or milligrams of the active constituent, an individual sample under investigation may only consist of micrograms or nanograms.
Alcohol gains access to the central nervous system by entering the blood stream through the lining of the stomach and small intestine.
The absorbed alcohol can diminish reflexes, disrupt nerve impulses, prolong muscle responses, and impact various other physiological functions throughout the body.
Upon entering the bloodstream, it rapidly reaches the brain within minutes, causing a significant surge in dopamine levels.
The rapid increase in dopamine levels during use contributes to a pronounced and challenging comedown, often prompting individuals to seek higher doses in subsequent use to achieve the same effects as experienced previously.
Chemicals in the bloodstream may be transferred to the growing hair and stored in the follicle, providing a rough timeline of drug intake events.
A common autopsy sample is the gastric contents of the deceased, which can be useful for detecting undigested pills or liquids that were ingested prior to death.
As an alternative to immunoassay screening which generally requires confirmation with another technique, LC-MS offers greater selectivity and sensitivity.
This subsequently reduces the possibility of a false negative result that has been recorded in immunoassay drug screening with synthetic cathinones and cannabinoids.
However, recent advances in LC-MS have led to higher resolution and sensitivity which assists in the evaluation of spectra to identify forensic analytes.
[20] The compounds suspected of containing a metal are traditionally analyzed by the destruction of the organic matrix by chemical or thermal oxidation.
This leaves the metal to be identified and quantified in the inorganic residue, and it can be detected using such methods as the Reinsch test, emission spectroscopy or X-ray diffraction.
