Forensic Toxicology - the study of the chemical and physical properties of toxic substances and their physiological effect on living organisms
Three Primary Responsibilities 1.Postmortem Drug Testing 2.Workplace Drug Testing 3.Identification of Contraband Materials
Deaths Investigated by Toxicologists 1.Accidental Poisonings 2.Drug Abuse Cases 3.Suicidal Poisonings 4.Homicidal Poisonings
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
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.Metallic Poisons 3.Volatile Organics 4.Non-volatile Organics - the major category here is what is known as an alkaloid, a drug that mimics human neurotransmitters or hormones and therefore interferes with normal body chemistry Alkaloids are derived from plants…
Alkaloids Common Examples: Amphetamines – stimulants that provoke euphoria; these drugs mimic catecholamines in the human body (adrenaline, etc) Cocaine – natural stimulant that acts as a mimic to catecholamines; metabolites are detected in urine for as many as 3 days Opiates – depressants that reduce muscle activity, heartbeat, respiration, and the inclination to sleep; effective pain relievers and euphoria producing; opiates mimic endorphins in the human body Cannabinoids – fast acting plant alkaloid; body mimic is unknown; metabolites can be detected in urine for months
Alkaloids adrenaline amphetamine cocaine ecstasy serotonin
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
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
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
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
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
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
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 IR Spectrum
Methods of Detection 5.Mass Spectroscopy 6.Immunoassay
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?