Forensic toxicology (student version)

Forensic ToxicologyForensic ToxicologyBy- Dr. Armaan SinghBy- Dr. Armaan Singh

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

living organisms

Three Primary Responsibilities Three Primary Responsibilities

1. Postmortem Drug Testing

2. Workplace Drug Testing

3. Identification of Contraband Materials

Deaths Investigated by ToxicologistsDeaths Investigated by Toxicologists

1. Accidental Poisonings

2. Drug Abuse Cases

3. Suicidal Poisonings

4. Homicidal Poisonings

Deaths Investigated by ToxicologistsDeaths Investigated by Toxicologists

1. Accidental Poisonings

2. Drug Abuse Cases

3. Suicidal Poisonings

4. Homicidal Poisonings

Toxicological Analysis of TissueToxicological 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 TissueToxicological 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 PoisonsGeneral 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…

AlkaloidsAlkaloids

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

AlkaloidsAlkaloids

adrenaline

amphetamine

cocaine

ecstasy

serotonin

Methods of DetectionMethods 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 light d. X-ray

b. visible light e. infrared

c. microwave

Methods of DetectionMethods 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 light d. X-ray

b. visible light e. infrared

c. microwave

Methods of DetectionMethods 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 light d. X-ray

b. visible light e. infrared

c. microwave

Methods of DetectionMethods 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 light d. X-ray

b. visible light e. infrared

c. microwave

Methods of DetectionMethods 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 light d. X-ray

b. visible light e. infrared

c. microwave

Methods of DetectionMethods 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 light d. X-ray

b. visible light e. infrared

c. microwave

Example UV-vis Spectrum

Methods of DetectionMethods 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 light d. X-ray

b. visible light e. infrared

c. microwave

Example IR Spectrum

Methods of DetectionMethods of Detection

5. Mass Spectroscopy

6. Immunoassay

Methods of DetectionMethods of Detection

5. Mass Spectroscopy

6. Immunoassay

Interpretation of FindingsInterpretation 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?