Forensic Toxicology -t-the study of the chemical and physical properties of toxic substances and their physiological effect on living organisms by Ondřej Stejskal
Deaths Investigated by Toxicologists 1.Accidental Poisonings 2.Drug Abuse Cases 3.Suicidal Poisonings 4.Homicidal Poisonings
Toxicological Analysis of Tissue a.Collect sample of all body fluids b.Collect samples from organs and tissues c.A forensic toxicologist cannot simply look for the presence of a toxin or drug in a body, she must understand how the body processes these molecules d.Toxicological analysis must start as soon as possible after a person’s death
General Classes of Poisons 1.Gases 2.Steam Volatile Poisons 3.Metallic Poisons 4.Non-volatile Organics - acids- alkaloids - bases- other biologicals - neutrals - amphoterics
Methods of Detection 1.Color test 2.Microdiffusion test 3.Chromatography a. thin-layer chromatography (TLC) b. gas chromatography (GC) c. high performance liquid chromatography (HPLC) 4.Spectroscopy a. UV lightd. X-ray b. visible lighte. infrared c. microwave
Example UV-vis Spectrum
Example IR Spectrum
Methods of Detection 5.Mass Spectroscopy 6.Immunoassay
Interpretation of Findings 1.Is a drug or poison present? What substance? 2.How much of the substance is present? Is it’s concentration in the body sufficient to cause death? 3.How was the drug/poison administered?