Toxicology: Overview and Applications

Toxicology in the context of a police or court-ordered investigation applies to the detection of drugs and other poisons in samples provided to the forensic toxicology laboratory. It is used to assist death investigators in establishing the cause and manner of death and, in the case of living subjects, to ascertain whether use of or exposure to substances has affected their clinical state, for example, their ability to safely drive motor vehicles to properly defend themselves against a criminal act. Analysts usually conduct two or more tests to not only cover a wide range of substances that might have relevance in a forensic case but also provide sufficient proof of identity of a foreign substance to meet the needs of the law. Analytical techniques employed include a combination of immunoassay, chromatographic, and mass spectrometric methods. The range of compounds to be targeted should include common legal drugs that have the potential to harm or cause behavioral changes, such as benzodiazepines and other sedatives/hypnotics, antidepressants, antipsychotics, and anticonvulsants, and illicit substances such as the amphetamines, cocaine, cannabis, and opiate-like drugs. Other substances available in the community may also be targeted in some cases.