Download Unit #7

Unit #7
Drugs, Alcohol,
and Toxicology
“Having sniffed the dead man’s lips, I
detected a slightly sour smell, and I
came to the conclusion that he had
poison forced upon him.”
—Sherlock Holmes, in Sir Arthur Conan Doyle’s
A Study in Scarlet
Unit # 7 - Drugs, Alcohol, and
Toxicology
1
Drugs
Students will learn:
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How to apply deductive
reasoning to a series of
analytical data.
The limitations of presumptive
(screening) tests.
The relationship between the
electromagnetic spectrum and
spectroscopic analysis.
The dangers of using
prescription drugs, controlled
substances, over-the-counter
medications, and illegal drugs.
Unit # 7 - Drugs, Alcohol, and
Toxicology
2
Drugs
Students will be able to:
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Chemically identify illicit
drug types.
Classify the types of illicit
drugs and their negative
effects.
Discuss the federal
penalties for possession
and use of controlled
substances.
Explain the need for
confirmatory tests.
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Toxicology
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Drugs
 Describe IR, UV-VIS
spectroscopy, and GC-MS
 Present and interpret data
with graphs.
 Use the Physicians’ Desk
Reference (PDR) to
identify pills.
 Use technology and
mathematics to improve
investigations and
communications.
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Toxicology
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Drugs and Crime
 A drug is a natural or synthetic substance
designed to affect the subject psychologically or
physiologically.
 “Controlled substances” are drugs that are
restricted by law
 Controlled Substances Act is a law that was
enacted in 1970; it lists illegal drugs, their category
and their penalty for possession, sale or use.
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Toxicology
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Controlled Substances Act
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Schedule I—high potential for abuse; no currently acceptable
medical use in the US; a lack of accepted safety for use under
medical supervision
Schedule II—high potential for abuse; a currently accepted
medical use with severe restrictions; abuse may lead to severe
psychological or physical dependence
Schedule III—lower potential for abuse than the drugs in I or II; a
currently accepted medical use in the US; abuse may lead to
moderate physical dependence or high psychological dependence
Schedule IV—low potential for abuse relative to drugs in III; a
currently accepted medical use in the US; abuse may lead to
limited physical or psychological dependence relative to drugs in III
Schedule V—low potential for abuse relative to drugs in IV;
currently accepted medical use in the US; abuse may lead to
limited physical or psychological dependence relative to drugs in IV
Unit # 7 - Drugs, Alcohol, and
Toxicology
6
Examples of Controlled
Substances and Their Schedule
Placement
 Schedule I—heroin (diacetylmorphine), LSD, marijuana,
ecstasy (MDMA)
 Schedule II—cocaine, morphine, amphetamines (including
methamphetamines), PCP, Ritalin
 Schedule III—intermediate acting barbiturates, anabolic
steroids, ketamine
 Schedule IV—other stimulants and depressants including
Valium, Xanan, Librium, phenobarbital, Darvon
 Schedule V—codeine found in low doses in cough medicines
Unit # 7 - Drugs, Alcohol, and
Toxicology
7
Identification of Drugs
 PDR—Physicians’ Desk Reference
 Field Tests—presumptive tests
 Laboratory Tests—conclusive
tests
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Toxicology
8
Human Components
Used for Drug Analysis
 Blood
 Liver tissue
 Urine
 Brain tissue
 Hair
 Kidney tissue
 Gastric Contents
 Spleen tissue
 Bile
 Vitreous Humor of the
Eye
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Toxicology
9
Physicians’ Desk
Reference
PDR—a physicians’ desk reference is used
to identify manufactured pills, tablets and
capsules. It is updated each year. This
can sometimes be a quick and easy
identifier of the legally made drugs that
may be found at a scene. The reference
book gives a picture of the drug, whether it
is a prescription, over the counter, or a
controlled substance; as well as more
detailed information about the drug.
Unit # 7 - Drugs, Alcohol, and
Toxicology
10
Drug Identification
Confirmatory tests
Screening or
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presumptive tests
Spectrophotometry
 Ultraviolet (UV)
 Visible
 Spot or color tests
 Microcrystalline test—  Infrared (IR)
a reagent is added  Mass spectrometry
that produces a
crystalline precipitate
which is unique for a
certain drug.
 Chromatography
Unit # 7 - Drugs, Alcohol, and
Toxicology
11
Presumptive Color Tests
 Marquis—turns purple in the
presence of most opium
derivatives and orange-brown
with amphetamines
 Dillie-Koppanyi—turns violetblue in the presence of
barbiturates
 Duquenois-Levine—turns a
purple color in the presence of
marijuana
 Van Urk—turns a blue-purple in
the presence of LSD
 Scott test—color test for
cocaine, blue
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Toxicology
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Chromatography
 A technique for separating mixtures into
their components
 Includes two phases—a mobile one that
flows past a stationary one.
 The mixture interacts with the stationary
phase and separates.
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Toxicology
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Types of Chromatography
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Paper
Thin Layer (TLC)
Gas (GC)
Pyrolysis Gas (PGC)
Liquid (LC)
High Pressure Liquid (HPLC)
Column
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Toxicology
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Paper Chromatography
 Stationary phase—paper
 Mobile phase—a liquid
solvent
Capillary action moves
the mobile phase
through the stationary
phase
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Toxicology
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Thin Layer
Chromatography
 Stationary phase—
a thin layer of coating
(usually alumina or
silica) on a sheet of
plastic or glass
 Mobile phase—
a liquid solvent
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Toxicology
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Retention Factor (Rf)
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This is a number that represents
how far a compound travels in a
particular solvent
It is determined by measuring
the distance the compound
traveled and dividing it by the
distance the solvent traveled.
If the Rf value for an unknown
compound is close to or the
same as that for the known
compound, the two compounds
are likely similar or identical (a
match).
Unit # 7 - Drugs, Alcohol, and
Toxicology
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Gas Chromatography
Phases
 Stationary—a solid or a
viscous liquid that lines a tube
or column
 Mobile—an inert gas like
nitrogen or helium
Analysis
 Shows a peak that is
proportional to the
quantity of the substance
present
 Uses retention time
instead of Rf for the
qualitative analysis
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Toxicology
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Uses of Gas
Chromatography
 Not considered a confirmation of a
controlled substance
 Used as a separation tool for mass
spectroscopy (MS) and infrared
spectroscopy (IR)
 Used to quantitatively measure the
concentration of a sample. (In a courtroom,
there is no real requirement to know the concentration
of a substance. It does not affect guilt or innocence).
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Toxicology
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Spectroscopy
 Spectroscopy—the interaction of electromagnetic
radiation with matter.
 Spectrophotometer—an instrument used to measure
and record the absorption spectrum of a chemical
substance.
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Toxicology
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Spectrophotometry
Components
 A radiation source
 A frequency selector
 A sample holder
 A detector to convert electromagnetic
radiation into an electrical signal
 A recorder to produce a record of the signal
Types
 Ultraviolet
 Visible
 Infrared
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Toxicology
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Infrared Spectometry
 Material absorbs energy in the near-IR region of the electromagnetic
spectrum.
 Compares the IR light beam before and after passing through a
transparent sample.
 Result—an absorption or transmittance spectrum
 Gives a unique view of the substance; like a fingerprint
Unit # 7 - Drugs, Alcohol, and
Toxicology
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Mass Spectrometry
Gas chromatography has one major drawback, it does
not give a specific identification. Mass spectrometry
cannot separate mixtures. By combining the two
(GCMS), constituents of mixtures can be specifically
identified.
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Toxicology
23
Mass Spectrometry
In a mass spectrometer, an electron
beam is directed at sample molecules in
a vacuum chamber. The electrons break
apart the sample molecules into many
positive charged fragments. These are
sorted and collected according to their
mass-to-charge ratio by an oscillating
electric or a magnetic field.
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Toxicology
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Mass Spectra
Each molecular species has its own
unique mass spectrum.
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Toxicology
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IR Spectrophotometry and
Mass Spectrometry
 Both work well in identifying pure
substances.
 Mixtures are difficult to identify in both
techniques
 Both are compared to a catalog of knowns
Unit # 7 - Drugs, Alcohol, and
Toxicology
26
People of Historical
Significance
Arthur Jeffrey Dempster was born in Canada, but studied and received
his PhD from the University of Chicago. He began teaching physics
there in 1916. In 1918, Dempster developed the first modern mass
spectrometer. His version was over 100 times more accurate than
previous ones developed, and established the basic theory and design
of mass spectrometers that is still used to this day.
Unit # 7 - Drugs, Alcohol, and
Toxicology
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People of Historical
Significance
Francis William Aston was a British physicist who won
the 1922 Nobel Prize in Chemistry for his work in the
invention of the mass spectrograph. He used a
method of electromagnetic focusing to separate
substances. This enabled him to identify no fewer
than 212 of the 287 naturally occurring elemental
isotopes.
Unit # 7 - Drugs, Alcohol, and
Toxicology
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Unit #7
Drugs, Alcohol, and
Toxicology
“All substances are poisons.
There is none which is not.
The right dose differentiates a
poison and remedy.”
—Paracelsus (1495-1541). Swiss
physician and chemist
Unit # 7 - Drugs, Alcohol, and
Toxicology
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Toxicology and Alcohol
Students will learn:
• A quantitative approach to
toxicology.
• The danger of using alcohol.
Unit # 7 - Drugs, Alcohol, and
Toxicology
30
Toxicology and Alcohol
Students will be able to:
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Discuss the connection of blood alcohol
levels to the law, incapacity, and test
results.
Understand the vocabulary of poisons.
Design and conduct scientific
investigations.
Use technology and mathematics to
improve investigations and
communications.
Identify questions and concepts that guide
scientific investigations.
Communicate and defend a scientific
argument.
Unit # 7 - Drugs, Alcohol, and
Toxicology
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Toxicology
Definition—the study of the adverse effects
of chemicals or physical agents on living
organisms.
Types:
– Environmental—air, water, soil
– Consumer—foods, cosmetics, drugs
– Medical, clinical, forensic
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Toxicology
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Forensic Toxicology
• Postmortem—medical examiner or
coroner
• Criminal—motor vehicle accidents (MVA)
• Workplace—drug testing
• Sports—human and animal
• Environment—industrial, catastrophic,
terrorism
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Toxicology
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Toxicology
Toxic substances may:
– Be a cause of death
– Contribute to death
– Cause impairment
– Explain behavior
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Toxicology
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Historical Perspective
of Poisoners
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Olympias—a famous Greek poisoner
Locusta—personal poisoner of Emperor Nero
Lucretia Borgia—father was Pope Alexander VI
Madame Giulia Toffana—committed over 600
successful poisonings, including two Popes.
• Hieronyma Spara—formed a society to teach women
how to murder their husbands
• Madame de Brinvilliers and Catherine Deshayes—
French poisoners.
AND many others through modern times.
Unit # 7 - Drugs, Alcohol, and
Toxicology
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The Severity of the Problem
“If all those buried in our cemeteries
who were poisoned could raise their
hands, we would probably be shocked
by the numbers.”
—John Harris Trestrail, “Criminal Poisoning”
Unit # 7 - Drugs, Alcohol, and
Toxicology
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People of Historical
Significance
Mathieu Orfila—known as
the father of forensic
toxicology, published in
1814 “Traite des Poisons”
which described the first
systematic approach to the
study of the chemistry and
physiological nature of
poisons.
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Toxicology
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Aspects of Toxicity
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Dosage
The chemical or physical form of the substance
The mode of entry into the body
Body weight and physiological conditions of the
victim, including age and sex
• The time period of exposure
• The presence of other chemicals in the body or
in the dose
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Toxicology
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Lethal Dose
• LD50—refers to the dose of a substance
that kills half the test population, usually
within four hours
• Expressed in milligrams of substance per
kilogram of body weight
Unit # 7 - Drugs, Alcohol, and
Toxicology
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Toxicity Classes
LD50 (rat,oral)
Correlation to
Ingestion by 150 lb
Adult Human
Toxicity
<1mg/kg
a taste to a drop
extremely
1-50 mg/kg
to a teaspoon
highly
50-500 mg/kg
to an ounce
moderately
500-5000 mg/kg
to a pint
slightly
5-15 g/kg
to a quart
practically non-toxic
Over 15g/kg
more than 1 quart
relatively harmless
Unit # 7 - Drugs, Alcohol, and
Toxicology
40
Federal Regulatory
Agencies
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Food and Drug Administration (FDA)
Environmental Protection Agency (EPA)
Consumer Product Safety Commission
Department of Transportation (DOT)
Occupational Safety and Health
Administration (OSHA)
Unit # 7 - Drugs, Alcohol, and
Toxicology
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Symptoms of Various Types
of Poisoning
Type of Poison
Symptom/Evidence
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Caustic Poison (lye)
•
Carbon Monoxide
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Sulfuric acid
Hydrochloric acid
Nitric acid
Phosphorous
Cyanide
Arsenic, Mercury
Methyl (wood) or
Isopropyl (rubbing) alcohol
Characteristic burns around the lips and
mouth of the victim
Red or pink patches on the chest and thighs,
unusually bright red lividity
Black vomit
Greenish-brown vomit
Yellow vomit
Coffee brown vomit. Onion or garlic odor
Burnt almond odor
Pronounced diarrhea
Nausea and vomiting, unconsciousness,
possibly blindness
Unit # 7 - Drugs, Alcohol, and
Toxicology
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Critical Information
on Poisons
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Form
Common color
Characteristic odor
Solubility
Taste
Common sources
Lethal dose
Mechanism
Possible methods of administration
Time interval of onset of
symptoms.
•
Symptoms resulting from an acute
exposure
• Symptoms resulting from chronic
exposure
• Disease states mimicked by
poisoning
• Notes relating to the victim
• Specimens from victim
• Analytical detection methods
• Known toxic levels
• Notes pertinent to analysis of
poison
• List of cases in which poison was
used
—John Trestrail from “Criminal Poisoning”
Unit # 7 - Drugs, Alcohol, and
Toxicology
43
To Prove a Case
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Prove a crime was committed
Motive
Intent
Access to poison
Access to victim
Death was caused by poison
Death was homicidal
Unit # 7 - Drugs, Alcohol, and
Toxicology
44
Forensic Autopsy
Look for:
– Irritated tissues
– Characteristic odors
– Mees lines—single transverse white bands on nails.
Order toxicological screens
– Postmortem concentrations should be done at the
scene for comparison
– No realistic calculation of dose can be made from a
single measurement
Unit # 7 - Drugs, Alcohol, and
Toxicology
45
Human Specimens for
Analysis
• Blood
• Urine
• Vitreous Humor of
Eyes
• Bile
• Gastric contents
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•
•
•
Liver tissue
Brain tissue
Kidney tissue
Hair/nails
Unit # 7 - Drugs, Alcohol, and
Toxicology
46
Alcohol—Ethyl Alcohol
(C2H5OH)
• Most abused drug in America
• About 40% of all traffic deaths are alcohol-related
• Toxic—affecting the central nervous system, especially
•
•
•
•
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the brain
Colorless liquid, generally diluted in water
Acts as a depressant
Alcohol appears in blood within minutes of consumption;
30-90 minutes for full absorption
Detoxification—about 90% in the liver
About 5% is excreted unchanged in breath, perspiration
and urine
Unit # 7 - Drugs, Alcohol, and
Toxicology
47
Rate of Absorption
Depends on:
– amount of alcohol consumed
– the alcohol content of the beverage
– time taken to consume it
– quantity and type of food present in the
stomach
– physiology of the consumer
Unit # 7 - Drugs, Alcohol, and
Toxicology
48
BAC
Blood Alcohol Content
• Expressed as percent weight per volume of
blood
• Legal limits in all states is 0.08%
• Parameters influencing BAC:
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Body weight
Alcoholic content
Number of beverages consumed
Time between consumption
Unit # 7 - Drugs, Alcohol, and
Toxicology
49
BAC
• Burn off rate of 0.015% per hour but can
vary:
 Male
BAC male = 0.071 x (oz) x (% alcohol)
body weight
 Female
BAC female = 0.085 x (oz) x (% alcohol)
body weight
Unit # 7 - Drugs, Alcohol, and
Toxicology
50
Henry’s Law
• When a volatile chemical is dissolved in a liquid and is
brought to equilibrium with air, there is a fixed ratio
between the concentration of the volatile compound in
the air and its concentration in the liquid; this ratio is
constant for a given temperature. THEREFORE, the
concentration of alcohol in breath is proportional to that in
the blood.
• This ratio of alcohol in the blood to alcohol in the alveolar
air is approximately 2100 to 1. In other words 1 ml of
blood will contain nearly the same amount of alcohol as
2100 ml of breath.
Unit # 7 - Drugs, Alcohol, and
Toxicology
51
Field Tests
• Preliminary tests—used to determine the degree of
suspect’s physical impairment and whether or not
another test is justified.
• Psychophysical tests—3 Basic Tests
 Horizontal gaze nystagmus (HGN): follow a pen or small
flashlight, tracking left to right with one’s eyes. In general,
wavering at 45 degrees indicates 0.10 BAC.
 Nine Step walk and turn (WAT): comprehend and execute
two or more simple instructions at one time.
 One-leg stand (OLS): maintain balance, comprehend and
execute two or more simple instructions at one time.
Unit # 7 - Drugs, Alcohol, and
Toxicology
52
The Breathalyzer
• More practical in the field
• Collects and measures alcohol content of alveolar breath
• Breath sample mixes with 3 ml of 0.025 % K2Cr2O7 in sulfuric
acid and water
2K2Cr2O7 + 3C 2H5OH + 8H 2SO4  2Cr2(SO4)3 + 2K2SO4 + 3CH3COOH + 11 H2O
• Potassium dichromate is yellow, as concentration decreases its
light absorption diminishes so the breathalyzer indirectly
measures alcohol concentration by measuring light absorption of
potassium dichromate before and after the reaction with alcohol
Unit # 7 - Drugs, Alcohol, and
Toxicology
53
Generalizations
• During absorption, the concentration of alcohol in arterial
blood will be higher than in venous blood.
• Breath tests reflect alcohol concentration in the pulmonary
artery.
• The breathalyzer also can react with acetone (as found
with diabetics), acetaldehyde, methanol, isopropyl alcohol,
and paraldehyde, but these are toxic and their presence
means the person is in serious medical condition.
• Breathalyzers now use an infrared light absorption device
with a digital read-out. Prints out a card for a permanent
record.
Unit # 7 - Drugs, Alcohol, and
Toxicology
54
People in the News
John Trestrail is a practicing toxicologist
who has consulted on many criminal
poisoning cases. He is the founder of the
Center for the Study of Criminal Poisoning
in Grand Rapids, Michigan which has
established an international database to
receive and analyze reports of homicidal
poisonings from around the world. He is
also the director of DeVos Children’s
Hospital Regional Poison Center. In
addition, he wrote the book, Criminal
Poisoning, used as a reference by law
enforcement, forensic scientists and
lawyers.
Unit # 7 - Drugs, Alcohol, and
Toxicology
55