Forensic toxicology uses toxicology and analytical chemistry to aid in investigations of death, poisoning, and drug use. Samples commonly collected include blood, urine, hair, and contents of the gastrointestinal tract and organs like the liver and spleen. Blood is very important for determining recent exposure, while urine and hair can indicate longer-term drug or toxin exposure. Various analytical methods like gas-liquid chromatography are used to detect and identify toxins and drugs in samples.

1. Toxicology
Dr. Waseem Ishaq
Forensic Scientist

2. Toxicology

3. Toxicology
A method for detecting arsenous oxide, simple arsenic, in corpses was devised in
1773 by the Swedish chemist Carl Wilhelm Scheele. His work was expanded, in
1806, by German chemist Valentin Ross, who learned to detect the poison in the
walls of a victim's stomach.

4. Forensic toxicology is the use of toxicology and disciplines such as analytical
chemistry, pharmacology and clinical chemistry to aid medical or legal
investigation of death, poisoning, and drug use.
Forensic Toxicology

5. Types of samples collected in forensic toxicology
• The most common sample types used by forensic toxicologists are
• Blood
• Urine
• Hair
Post-mortem sample collection also frequently includes an examination of the
contents of the gastrointestinal tract, which is likely to contain evidence of
consumed drugs or toxins that are yet to be digested.
The liver, spleen, vitreous of the eye, and brain may also hold valuable information
regarding the cause of death.
Forensic Toxicology

6. Types of samples collected in forensic toxicology
Blood is considered to be among the most important of all samples in
forensic toxicology, and it is recommended that samples be collected
from both the heart and an extremity in post-mortem cases, as trauma
or the diffusion of drugs through tissue may contaminate the sample.
Urine samples provide strong evidence of the past consumption of
many drugs and other compounds, a majority of which will linger in the
urine for longer than in blood due to the gradual rate at which they are
metabolized.
Forensic Toxicology

7. Types of samples collected in forensic toxicology
Hair is useful when determining long-term exposure and even the date
of exposure to toxins or drugs, as traces of metabolites are
incorporated into the hair through the follicles as it grows.
The vitreous humour, the gel-like substance contained within the eye,
is highly stable for several months following death and has been used
to provide evidence of the consumption of a variety of drugs, including
cocaine.
Forensic Toxicology

8. Types of samples collected in forensic toxicology
Many drugs and toxins will at some point pass through the liver, and
can accumulate there, examination of the hepatobiliary system is often
highly informative.
This system also includes the spleen, which contains a reserve of red
blood cells that are frequently used to determine carbon monoxide
exposure.
Forensic Toxicology

9. How are toxins detected?
A wide variety of analytical methods are utilized to qualitatively, and
sometimes quantitatively, determine the presence of drugs or toxins in
an individual’s body.
Gas-liquid chromatography is among the most versatile and useful of
these methods, as it serves to separate multiple compounds from one
another in a sample.
For example, track marks on the body of an individual imply the use of
intravenous drugs.
Forensic Toxicology

10. Thank You