This document provides an overview of the history and applications of forensic toxicology. It discusses how forensic toxicology has evolved from early uses of poisons in hunting thousands of years ago to the establishment of modern toxicology labs and practices in the early 20th century. It also describes the roles and responsibilities of forensic toxicologists, including collecting evidence, analyzing tissues and body fluids, and investigating poisoning cases. The key applications of forensic toxicology are identified as postmortem analysis, human performance/behavioral toxicology, and forensic drug testing.

1. Seema Bansal

2. HISTORY
 50000 BC: used poisonous plants for hunting
 1500 BC: written evidence indicated opium, curare
and metals were used for hunting
 Mathieu Orifila: father of forensic toxicology,
published Traite des Poisons, in 1814.
 Jean Servais Stat: isolated nicotine from dead man’s
tissue
 James M. Marsh: test for presence of arsenic in tissues
in 1836
 Medical examiner’s office and toxicology laboratory
established in New York in 1918

3. TOXICOLOGY
 Science of poisons
 Toxicology is the study of the toxic or harmful effects
of chemicals on humans
 Involves the identification of the substances involved.
 Paracelsus is the Father of Toxicology. According to
him “All things are poison, nothing is without poison,
what matters is the dose”

4. Poison: Any substance which when administered in
living body through any route (Inhalation, Ingestion,
surface absorption, etc) will produce ill-health or
death by its action which is due to its physical,
chemical or physiological properties. Eg: sulphuric
acid, arsenic etc.
Drug (WHO 1996): Any substance or product that
is used or intended to be used to modify or explore
physiological systems or pathological states for the
benefit of the recipient.
Eg: parecetamol, salbutamol, insulin

5. FORENSIC SCIENCE
 Forensic: synonym for “legal”
or “related to courts”
 Answer questions of interest to
a legal system
 It is concerned with the
recognition, identification,
individualization, and
evaluation of physical
evidence.

6. Toxicology is defined as the study of the adverse
effects of chemicals on living organisms.
Forensic toxicology is defined as the application of
toxicology for the purposes of the law.
Postmortem forensic toxicology.
Human performance toxicology.
Forensic drug testing.
FORENSIC TOXICOLOGY

7. FORENSIC TOXICOLOGY
 Hybrid of analytical chemistry and fundamental
toxicological principles concerned with the
medicolegal aspects of the harmful effects of
chemicals on living system.
 Toxicological principles are:
 Study of alcohol, drugs and poisons, including their
chemical composition, preparations and
identification.
 Knowledge about the ADME of above substances
and the factors which determine drug safety and
effectiveness.

8. FORENSIC TOXICOLOGIST
 Members of medico legal team
 Specialized scientists
RESPONSIBILITIES:
 Collection of evidence
 Preservation of samples
 Investigation
 Oral / written reports

9. DEATH SCENE IN LAB
Medico legal investigation team
 The homicide investigator
 The medical examiner
 The forensic pathologist
 The forensic toxicologist
 Proper labeling
 Storage (for collection/ preservation)

10. COLLETION AND
PRESERVATION OF SPECIMENS
 Obtain
 Appropriate container
 Sealing
 Dated & signed
 Taken to laboratory
 Receiving by toxicologist(signed, date and time
recorded)
 Chain of possession must be intact, guaranteeing
complete chronological accountability

11. TOXICOLOGY WORKSHEET

12. TISSUES REQUIRED FOR
ANALYSIS
 BLOOD: 100 ml sample sufficient
Care taken to ensure freedom from
contamination
Heart blood preferred, peripheral blood accepted
 BRAIN: 50 g
Demonstration of alcohol and volatile poisons
KIDNEY: equivalent of one kidney
 Choice for most metals and sulphonamides

13. •LIVER: 100g sample
Site of biotransformation-higher levels found.
•LUNG: 100g
Useful in fatalities due to substance inhalation.
•BONE: 100g
Pesticide or metal suspected.
•HAIR AND NAILS:
chronic metal poisoning suspected.
•URINE:
 available urine collected, if empty, entire
bladder submitted.
Microsugar and acetone determination.

14. •BILE: removed intact
Important route of elimination for many
drugs(morphine, methadone)
•STOMACH CONTENTS:
tablets and capsules in overdose case
Volume of contents recorded

15. LABORATORY ANALYSIS
 Colorimetric screening tests
 Thermal desorption
 Thin layer chromatography
 Gas chromatography
 High performance liquid chromatography
 Enzyme immunoassay
 Atomic absorption spectroscopy

16. DRUG ANALYSIS

17. APPLICATIONS
Identify potential suspects by DNA matching.
Identify crime & catastrophe victims.
Establish Paternity & family relationship.
Identify endangered & protected species.
Detect bacteria & other organism that can pollute
environment.
In transplant programs.

18.  Human performance toxicology is also referred to as
behavioral toxicology; study of human behavior
under the drug influence.
.
 Ethanol and driving
History
Behavioral effect
Specimen
HUMAN PERFORMANCE
TOXICOLOGY

19. ETHANOL TOXICOLOGY
• Cardiovascular System
• Central Nervous
System
• Gastrointestinal Tract
• Kidney
• Liver
ADR OF ETHANOL:

20. Henry’s Law
Ethanol in breath Vs ethanol in blood
2100 to 1 ratio
2300 to 1 ratio
Types of Analyser
Chemical
Reaction of ethanol with potassium
dichromate/sulfuric acid solution
Colored solution that results is measured
spectrophotometrically
IR spectrophotometry
Electrochemical oxidation - fuel cell
BREATH ETHANOL TESTING
Theory

21. BLOOD ETHANOL TESTING
Chemical
 Screening
 Quantitative
 Disadvantage -
aldehydes and
ketones will interfere
with the test
 Enzymatic
• Conversion of NAD to
NADH by ethanol (serum,
urine and whole blood)
 Measured
spectrophotometrically
at 340 nm
• Same reaction with a blue
dye (thiazoyl blue) (serum,
urine, fresh blood and
postmortem blood)
 Measured with a
fluorometer

22. Gas Chromatography
•Can measure ethanol in a wide
range of specimens
•Can distinguish ethanol from
other alcohols, aldehydes and
ketones
•Two common methods
•Head space
•Direct injection
ACETALDEHYDE
(1.414
min.)
EHTANOL
(1.787
min.)
2-PROPANOL
(2.804
min.)
MEK(ISTD)
(5.584
min.)
ACETONE
(2.462
min.)
0 6
BLOOD ETHANOL TESTING

23.  Blood alcohol concentration:
 10-50 mg/dl: Impairment detectable by special tests
 30-120 mg/dl: Beginning of sensory-motor
impairment
 90-250 mg/dl: Sensory-motor in coordination ;
impaired balance
 180-400 mg/dl: Increased muscular in coordination;
apathy; lethargy
 250-400 mg/dl: Impaired consciousness; sleep; stupor
 350-500 mg/dl: Complete unconsciousness; coma
 450 and greater mg/dl: Death from respiratory arrest
ETHANOL IMPAIRMENT
ASSESSMENT

24. Drug Recognition Evaluation - 12 Steps
Breath alcohol test
Interview of the arresting officer.
Preliminary examination of the suspect.
Examination of the eyes.
Divided attention psychophysical tests.
Vital signs examination.
Dark room examination.
Examination of muscle tone.
Examination for injection sites.
Suspect’s statements and other observations.
Opinion of the evaluator.
Toxicological examination.
FORENSIC DRUG TESTING

25. REFERENCES
 Wennig R. Forensic Toxicology. Encyclopedia of Life
Sciences
 Hodgson E. A Textbook of Modern Toxicology.2004(3):
403-406
 Katzung BG, Masters SB, Trevor AJ. Basic and Clinical
Pharmacology. (2012)12: 69-77
 Journal of forensic toxicology and pharmacology; 2013