Forensic Toxicology

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Forensic Toxicology

• - the study of the chemical and physical
  properties of toxic substances and their
  physiological effect on living organisms

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Three Primary Responsibilities

1. Postmortem Drug Testing
2. Workplace Drug Testing
3. Identification of Contraband Materials

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Deaths Investigated by Toxicologists

1. Accidental Poisonings
2. Drug Abuse Cases
3. Suicidal Poisonings
4. Homicidal Poisonings

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Deaths Investigated by Toxicologists

1. Accidental Poisonings
2. Drug Abuse Cases
3. Suicidal Poisonings
4. Homicidal Poisonings

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Toxicological Analysis of Tissue

1. Collect sample of all body fluids
2. Collect samples from organs and tissues
3. 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
4. Toxicological analysis must start as soon as
   possible after a persons death

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Toxicological Analysis of Tissue

1. Collect sample of all body fluids
2. Collect samples from organs and tissues
3. 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
4. Toxicological analysis must start as soon as
   possible after a persons death

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General Classes of Poisons

• Gases
• Metallic Poisons
• Volatile Organics
• 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

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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

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Alkaloids
amphetamine
adrenaline
cocaine
serotonin
ecstasy
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Methods of Detection

• Color test
• Microdiffusion test
• Chromatography
• a. thin-layer chromatography (TLC)
• b. gas chromatography (GC)
• c. high performance liquid chromatography (HPLC)
• Spectroscopy
• a. UV light d. X-ray
• b. visible light e. infrared
• c. microwave

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Methods of Detection

• Color test
• Microdiffusion test
• Chromatography
• a. thin-layer chromatography (TLC)
• b. gas chromatography (GC)
• c. high performance liquid chromatography (HPLC)
• Spectroscopy
• a. UV light d. X-ray
• b. visible light e. infrared
• c. microwave

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Methods of Detection

• Color test
• Microdiffusion test
• Chromatography
• a. thin-layer chromatography (TLC)
• b. gas chromatography (GC)
• c. high performance liquid chromatography (HPLC)
• Spectroscopy
• a. UV light d. X-ray
• b. visible light e. infrared
• c. microwave

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Methods of Detection

• Color test
• Microdiffusion test
• Chromatography
• a. thin-layer chromatography (TLC)
• b. gas chromatography (GC)
• c. high performance liquid chromatography (HPLC)
• Spectroscopy
• a. UV light d. X-ray
• b. visible light e. infrared
• c. microwave

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Methods of Detection

• Color test
• Microdiffusion test
• Chromatography
• a. thin-layer chromatography (TLC)
• b. gas chromatography (GC)
• c. high performance liquid chromatography (HPLC)
• Spectroscopy
• a. UV light d. X-ray
• b. visible light e. infrared
• c. microwave

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Methods of Detection

• Color test
• Microdiffusion test
• Chromatography
• a. thin-layer chromatography (TLC)
• b. gas chromatography (GC)
• c. high performance liquid chromatography (HPLC)
• Spectroscopy
• a. UV light d. X-ray
• b. visible light e. infrared
• c. microwave

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Example UV-vis Spectrum
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Methods of Detection

• Color test
• Microdiffusion test
• Chromatography
• a. thin-layer chromatography (TLC)
• b. gas chromatography (GC)
• c. high performance liquid chromatography (HPLC)
• Spectroscopy
• a. UV light d. X-ray
• b. visible light e. infrared
• c. microwave

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Example IR Spectrum
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Methods of Detection

1. Mass Spectroscopy
2. Immunoassay

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Methods of Detection

1. Mass Spectroscopy
2. Immunoassay

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Interpretation of Findings

1. Is a drug or poison present? What substance?
2. How much of the substance is present? Is its
   concentration in the body sufficient to cause
   death?
3. How was the drug/poison administered?