Chapter 5
DRUGS
5-1
Introduction
• A drug can be defined as a natural or synthetic
substance that is used to produce physiological
or psychological effects in humans.
• This includes the two most widely used drugs in
America; Alcohol and Marijuana.
• Drug crimes cut across all aspects of society
• Because of their epidemic proportions, 75% of
evidence evaluated by crime labs is drug
related.
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N
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Narcotics
• The term, “narcotics" is often used to
refer to any illegal drug.
• That could include anything from
prescription pills to cocaine.
• However, "narcotics" does actually refer
to a specific type of drug as well.
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Narcotics
• Narcotics actually refers
to drugs that are
derived from opium
which originates from
the opium poppy plant.
• Common types of
narcotics include
barbituates, heroin,
opium in the form of
morphine and codeine,
oxycodone and Vicodin.
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Opiates
• Morphine is readily extracted from opium and
is used to synthesize heroin.
• Addicts frequently dissolve heroin in water by
heating it in a spoon, and then inject in the
skin.
• Heroin produces a “high” that is accompanied
by drowsiness and a sense of well-being that
generally last for three to four hours.
• Codeine is also present in opium, but it is
usually prepared synthetically from morphine.
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Other Opiates
• OxyContin, with the active ingredient
oxycodone, is not derived from opium or
morphine, but does have the same physiological
effects on the body as do opium narcotics.
• OxyContin is prescribed to a million patients
for treatment of chronic pain.
• Methadone is another well-known synthetic
opiate.
• Methadone, which is pharmacologically related
to heroin, appears to eliminate the addict’s
desire for heroin while producing minimal side
effects.
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•Hallucinogens
M
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Hallucinogens
• Another class of drugs is hallucinogens;
marijuana is the most well-known
member of this class.
• Hallucinogens cause marked changes in
normal thought processes, perceptions,
and moods.
• Marijuana is the most controversial drug
in this class because its long-term effects
on health are still largely unknown.
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Marijuana
• aunt mary, boom, chronic, dope, ganja,
gangster, grass, hash, herb, kif, mary
jane, pot, reefer, sinsemilla, skunk, and
weed
• Marijuana refers to a preparation
derived from the plant Cannabis.
• The chemical substance largely
responsible for the hallucinogenic
properties of marijuana is known as
tetrahydrocannabinol, or THC.
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Marijuana
• The THC content of Cannabis varies in
different parts of the plant, generally
decreasing in the following sequence:
resin, flowers, leaves, with little THC in
the stem, roots or seeds.
• The THC-rich resin is known as hashish.
• Marijuana does not cause physical
dependency, but the risk of harm is in
heavy, long-term use.
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Other Hallucinogens
• Other hallucinogens include LSD, mescaline,
PCP, psilocybin, and MDMA (Ecstasy).
• LSD is synthesized from lysergic acid, and can
cause hallucinations that can last for 12 hours.
• Phencyclidine, or PCP, is often synthesized in
clandestine laboratories and is often smoked,
ingested, sniffed.
• Phencyclidine is often mixed with other drugs,
such as LSD, or amphetamine, and is sold as a
powder (“angel dust”), capsule, or tablet.
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Depressants
• Depressants are a type
of drug that can take
several forms; however,
the most common type
is administered by
prescription. Many
people are prescribed
depressant drugs which
have beneficial effects
but wind up dependant
on them or addicted.
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Depressants
• Depressants are another class of drugs.
• Depressants are substances used to depress
the functions of the central nervous system.
• Depressants calm irritability and anxiety and
may induce sleep.
• These include alcohol (ethanol), barbiturates,
tranquilizers, and various substances that can
be sniffed, such as airplane glue, model
cement, or aerosol gas propellants such as
Freon.
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Depressants
• Alcohol (ethyl alcohol) enters the body’s
bloodstream and quickly travels to the brain,
where it acts to suppress the brain’s control of
thought processes and muscle coordination.
• Barbiturates, or “downers,” are normally taken
orally and create a feeling of well-being, relax the
body, and produce sleep.
• Tranquilizers, unlike barbiturates, produce a
relaxing tranquility without impairment of highthinking faculties or inducing sleep.
• Sniffing has immediate effects such as exhilaration,
but impairs judgment and may cause liver, heart,
and brain damage, or even death.
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Stimulants
• Stimulants are a
class of drugs
that elevate
mood, increase
feelings of wellbeing, and
increase energy
and alertness.
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Stimulants
• The drug classification of stimulants
includes amphetamines, sometimes
known as “uppers” or “speed,” and
cocaine, which in its free-base form is
known as crack.
• Stimulants are substances taken to
increase alertness or activity, followed by
a decrease in fatigue and a loss of
appetite.
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Stimulants
• Amphetamine and methamphetamine, often
injected intravenously, cause an initial “rush,”
followed by an intense feeling of pleasure.
• This is followed by a period of exhaustion and a
prolonged period of depression.
• Cocaine, extracted from the leaves of Erythroxylin
coca, causes increased alertness and vigor,
accompanied by the suppression of hunger, fatigue,
and boredom.
• Crack is cocaine mixed with baking soda and water,
then heated.
• Crack is often smoked in glass pipes, and like
cocaine stimulates the brain’s pleasure center.
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Club Drugs
• The term club
drugs refers to
synthetic drugs
that are used at
nightclubs, bars,
and raves (allnight dance
parties).
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Club Drugs
• Substances that are often used as club
drugs include, but are not limited to,
MDMA (Ecstasy), GHB (gamma
hydroxybutyrate), Rohypnol (“Roofies”),
ketamine, and methamphetamine.
• GHB and Rohypnol are central nervous
system depressants that are often
connected with drug-facilitated sexual
assault, rape, and robbery.
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E
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Ecstasy
• Methylenedioxymethamphetamine, also
known as MDMA or Ecstasy, is a
synthetic mind-altering drug that exhibits
many hallucinogenic and amphetaminelike effects.
• Ecstasy enhances self-awareness and
decreases inhibitions, however, seizures,
muscle breakdown, stroke, kidney
failure, and cardiovascular system failure
often accompany chronic abuse.
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Ketamine
• Ketamine is primarily used
as a veterinary animal
anesthetic that in humans
causes euphoria and
hallucinations.
• Ketamine can also cause
impaired motor functions,
high blood pressure,
amnesia, and mild
respiratory depression.
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Steroids
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Anabolic Steroids
• Yet another category of drugs is the anabolic
steroids.
• These are synthetic compounds that are
chemically related to the male sex hormone
testosterone.
• Anabolic steroids are often abused by
individuals who are interested in accelerating
muscle growth.
• Side effects include unpredictable effects on
mood and personality, depression, diminished
sex drive, halting bone growth, and liver
cancer.
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Drug Control Laws
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Drug-Control Laws
• The U.S. federal law known as the
Controlled Substances Act created a legal
drug-classification system to prevent and
control drug abuse.
• This federal law establishes five schedules
of classification for controlled dangerous
substances on the basis of a drug’s
– potential for abuse
– potential for physical and psychological
dependence
– medical value
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Schedules of Classification
• Schedule I — drugs with a high abuse
risk. These drugs have NO safe, accepted
medical use in the United States. Some
examples are:
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heroin
marijuana
LSD
PCP
crack cocaine
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Schedules of Classification
• Schedule II — drugs with a high abuse
risk, but also have safe and accepted
medical uses in the United States. These
drugs can cause severe psychological or
physical dependence. Schedule II drugs
include:
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morphine
cocaine
oxycodone (Percodan®)
methylphenidate (Ritalin®)
dextroamphetamine (Dexedrine®)
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Schedules of Classification
• Schedule III, IV, or V — drugs with an abuse
risk less than Schedule II. These drugs also
have safe and accepted medical uses in the
United States. Schedule III, IV, or V drugs
include those containing smaller amounts of
certain narcotics including:
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acetaminophen with codeine (Tylenol® No.3)
hydrocodone with acetaminophen (Vicodin®)
diazepam (Valium®)
alprazolam (Xanax®)
propoxyphene (Darvon®)
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Drug Identification
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Drug Identification
• The challenge or difficulty of forensic
drug identification comes in selecting
analytical procedures that will ensure a
specific identification of a drug.
• This plan, or scheme of analysis, is
divided into two phases.
– Preliminary screening test
– Confirmation test that is a single test that
specifically identifies a substance.
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Preliminary Analysis
• Faced with the prospect that the unknown
substance may be any one of a thousand or more
commonly encountered drugs, the analyst must
employ screening tests to reduce these
possibilities to a small and manageable number.
• This objective is often accomplished by
subjecting the material to a series of color tests
that will produce characteristic colors for the
more commonly encountered illicit drugs.
• Microcrystalline tests can also be used to identify
specific drug substances by studying the size and
shape of crystals formed when the drug is mixed
with specific reagents.
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Conformational Determination
• Once this preliminary analysis is completed, a
conformational determination is pursued.
• Forensic chemists will employ a specific test to
identify a drug substance to the exclusion of all
other known chemical substances.
• Typically infrared spectrophotometry or gas
chromatography-mass spectrometry is used to
specifically identify a drug substance.
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Qualitative vs. Quantitative
• Another consideration in selecting an
analytical technique is the need for either
a qualitative or a quantitative
determination.
• The former relates just to the identity of
the material, whereas the latter requires
the determination of the percent
composition of the components of a
mixture.
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Analytical Methods
GC
SP
TLC
MS
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Chromatography
• Chromatography is a means of separating and
tentatively identifying the components of a
mixture.
• The theory of chromatography is based on the
observation that chemical substances have a
tendency to partially escape into the surrounding
environment when dissolved in a liquid or when
absorbed on a solid surface.
• Those materials that have a preference for the
moving phase will slowly pull ahead and separate
from those substances that prefer to remain in
the stationary phase.
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Thin Layer Chromatography
• TLC uses a solid stationary phase usually coated
onto a glass plate and a mobile liquid phase to
separate the components of the mixture.
• The liquid will slowly rise up the plate by
capillary action causing the sample to become
distributed between the stationary phase and the
moving liquid phase.
• Because most compounds are colorless, the
materials must be visualized by placing the plates
under ultraviolet light or spraying the plate with
a chemical reagent.
• The distance a spot travels up a thin-layer plate
can be assigned a numerical value.
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Gas Chromatography
• In GC, the moving phase is actually a gas called
the carrier gas, which flows through a column.
• The stationary phase is a thin film of liquid
contained within the column.
• After a mixture has traversed the length of the
column, it will emerge separated into its
components.
• The written record of this separation is called a
chromatogram.
• The time required for a component to emerge
from a GC column is known as retention time.
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TLC data output
GC data output
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Spectrophotometry
• Just as a substance can absorb visible light to
produce color, many of the invisible radiations
of the electromagnetic spectrum are likewise
absorbed.
• Spectrophotometry, an important analytical
tool, measures the quantity of radiation that a
particular material absorbs as a function of
wavelength and frequency.
• The quantity of light absorbed at any
frequency is directly proportional to the
concentration of the absorbing species. This is
known as Beer’s Law.
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The Spectrophotometer
• The spectrophotometer is the instrument used
to measure and record the absorption spectrum
of a chemical substance.
• The components of a spectrophotometer are:
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A radiation source
A monochromator or frequency selector
A sample holder
A detector to convert electromagnetic radiation into
an electrical signal
– A recorder to produce a record of the signal
• Absorption spectra can be done in the visible,
ultraviolet (UV) or infrared (IR) regions.
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Spectrophotometry
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UV and IR Spectrophotometry
• Currently, most forensic laboratories use UV and
IR spectrophotometers to characterize chemical
compounds.
• The simplicity of the UV spectrum facilitates its
use as a tool for determining a material’s
probable identity, although it may not provide a
definitive result.
• The IR spectrum provides a far more complex
pattern.
• Different materials always have distinctively
different infrared spectra; each IR spectrum is
therefore equivalent to a “fingerprint” of that
substance.
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Mass Spectrometry
• In the mass spectrometer, a beam of high-energy
electrons collide with a material, producing
positively charged ions.
• These positive ions almost instantaneously
decompose into numerous fragments, which are
separated according to their masses.
• The unique feature of mass spectrometry is that
under carefully controlled conditions, no two
substances produce the same fragmentation
pattern.
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5-47
GC and Mass Spectrometer
• A direct connection between the GC
column and the mass spectrometer allows
each component to flow into the mass
spectrometer as it emerges from the GC.
• The separation of a mixture’s components
is first accomplished by the GC.
• Then, fragmentation of each component by
high-energy electrons in the mass
spectrometer, will produce a distinct
pattern, somewhat like a “fingerprint”, of
the substance being examined.
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