Transcript DRUGS

Chapter 5
DRUGS
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-1
Introduction
• A DON’T ASK / DON’T TELL POLICY IS IN
EFFECT; UNLESS YOU WANT TREATMENT
/ HELP FROM COUNSELORS.
• A drug can be defined as a natural or synthetic
substance that is used to produce physiological or
psychological effects in humans or other higher
order animals.
• Narcotic drugs are analgesics, meaning they
relieve pain by a depressing action on the central
nervous system. This effects functions such as
blood pressure, pulse rate and breathing rate.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-2
Drug-Control Laws
• The U.S. federal law known as the Controlled
Substances Act will serve to illustrate a legal
drug-classification system created 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
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-3
Schedules of Classification
• Schedule I drugs have a high potential for
abuse and have no currently accepted medical
use such as heroin, marijuana, methaqualone,
crystal meth, K2 and LSD.
• Schedule II drugs have a high potential for
abuse and have medical use with severe
restrictions such as cocaine, PCP, and most
amphetamine and barbiturate prescriptions.
This includes most ADHD medications,
Oxycontin, Fentanyl, Morphine,
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Schedules of Classification
• Schedule III drugs have less potential for abuse
and a currently accepted medical use such as
all barbiturate prescriptions not covered under
Schedule II, such as codeine and anabolic
steroids.
• Schedule IV drugs have a low potential for
abuse and have a current medical use such as
darvon, phenobarbital, and some tranquilizers
such as diazepam (valium) and
chlordiazepoxide (librium).
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-5
Schedules of Classification
• Schedule V drugs must show low abuse potential
and have medical use such as opiate drug mixtures
that contain nonnarcotic medicinal ingredients.
Codeine cough syrup is an example.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-6
Introduction
• The regular use of a narcotic drug will
invariably lead to physical dependence.
• The most common source for these narcotic
drugs is opium, extracted from poppies.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-7
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
or veins.
• Heroin produces a “high” that is accompanied
by drowsiness and a sense of well-being that
generally last for three to four hours.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-8
Opiates - Heroin
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-9
Opiates
• Codeine is also present in opium, but it is
usually prepared synthetically from morphine.
• 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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-10
Other Opiates
• 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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-11
Krokadil - Heroin
• The Texas DEA tells 1200 WOAI news that it
has experienced the first case of a Texan being
treated for using a new type of drug which
leaves the user with flesh lesions and turns the
skin a scaly green color.
• It is for that reason that the drug, known as
the 'poor man's heroin,' is known as 'krokadil,'
or 'crocodile.'
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-12
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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-13
Marijuana
• 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.
• 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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Marijuana 101
• •Short term effects
– –Problems with memory and learning,
distorted perception, and difficulty in
thinking and problem-solving
– –Loss of coordination
– •Impairs driving abilities
• •High doses
– –Mental confusion, panic reactions and
hallucinations
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-15
Marijuana 101
• Short term physical effects
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•Sedation
•Blood shot eyes
•Increased heart rate
•Coughing
•Increased appetite
•Decreased blood pressure
•Bronchitis
•Bronchial asthma
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-16
Marijuana
• The THC-rich Marijuana does not cause
physical dependency, but the risk of harm is in
heavy, long-term use to lungs and memory.
• Marijuana is a Federal Class I drug (Totally
Illegal). Some individual states have legalized
it for medical and recreational purposes.
Question: Who wins? Feds or State?
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-17
Commercial Medical THC
• THC: Available Medications: •Marinol®
– –The only drug currently approved by the
FDA that contains the synthetic form of
THC. Available through prescription in pill
form
– –Used to:
• •Relieve nausea and vomiting associated with
chemotherapy for cancer patients
• •Assist with loss of appetite in AIDS patients.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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THC Medications: Sativex
• THC: Available Medications: •Sativex®
– –Approved in June 2010 for use in ONLY
Canada and UK (NOT USA)
– –Oralmucosal spray for treatment of
spasticity due to Multiple Sclerosis
– •Contains THC and cannabidiol (CBD)
– •Grown in a structured and scientific
environment. Administers a set dosage
• •Reduces the intoxicating effects
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-19
Medical Marijuana in USA
• Nov 2, 2010: Arizona Became the 14th
State to Legalize Medical Marijuana Alaska
Arizona California Colorado Hawaii Maine
Michigan Montana Nevada New Mexico
Oregon Vermont Rhode Island Washington
•
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-20
Medical Example: Arizona
• Arizona Medical Marijuana Act:
• •Requires registry identification cards
• •Limits the number of dispensaries
• Includes several requirements for physicians who
may provide patients with written prescriptions.
• •Requires dispensaries to appoint an individual who
is a physician to function as a medical director
• •Requires dispensaries to develop, document, and
implement policies and procedures regarding
inventory control
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-21
Medical Requirements for Pot
• Must have one of the following qualifying
conditions:
– –Cancer, glaucoma, HIV, AIDS, Hepatitis C,
Amyotrophic Lateral Sclerosis, Crohn’s
disease, Agitation of Alzheimer’s disease, or
– –A chronic or debilitating disease or medical
condition (or the treatment for) that causes:
– •severe and chronic pain, severe nausea,
•seizures, severe or persistent muscle spasms
or a debilitating medical condition.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Qualifying Patients
• •A qualified patient may possess up to 2.5
ounces of usable marijuana in 14 days.
– •May not smoke it in public places, including
dispensaries
– •May eat it in foods or use infused products
– •Cannot drive a motor vehicle under the influence
– •If eligible to cultivate: may have up to 12
marijuana plants
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After the first 16 months since implementation in Arizona:
•31,112 Qualifying Patients approved
•27% female, 73% male
•28 qualifying patients are under 18 yo
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-23
Legal Recreational Pot
• Historically the USA has kept Pot illegal.
• In 2012 Voters in Washington and
Colorado passed ballot initiatives
Tuesday to legalize marijuana for
recreational use. The Federal
Government has not changed its
classification of pot yet. It is still
• ILLEGAL. Job Drug Screening
Money
Magazine link
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-24
Synthetic Marijuana
• Synthetic cannabis is a psychoactive
designer drug created by spraying
natural herbs with synthetic chemicals
that, when consumed, allegedly mimic the
effects of cannabis. It is often known by
the brand names K2[1] and Spice.
• The ingredients contained in these
products are mimics or isomers, not
copies of THC.[3]
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Synthetic Marijuana
• K2 may trigger a chronic (long-term)
psychotic disorder among vulnerable
individuals such as those with a family
history of mental illness.
• Safety of the drug has not been
established by studies, but reports of
reactions have occurred.
• Link news
• Video link
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-26
Other Hallucinogens
• Other hallucinogens include LSD, mescaline,
PCP, psilocybin, and MDMA (Ecstasy).
• LSD is synthesized from lysergic acid, a fungus
by-product, and can cause hallucinations that
can last for 12 hours. You can have sudden
“flashbacks” years after a single use.
• Phencyclidine, or PCP, is often synthesized in
clandestine laboratories and is often smoked,
ingested, sniffed.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-27
Other Hallucinogens
• Phencyclidine is often mixed with other drugs,
such as LSD, or amphetamine, and is sold as a
powder (“angel dust”), capsule, or tablet.
• Oral intake of PCP first leads to feelings of
strength and invulnerability, which may turn
to depression, tendencies toward violence, and
suicide.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Depressants
• 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.
• 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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Depressants
• 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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Stimulants
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Stimulants
• 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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-35
Club Drugs
• The term club drugs refers to synthetic drugs
that are used at nightclubs, bars, and raves (allnight dance parties).
• 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 drugfacilitated sexual assault, rape, and robbery.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Club Drugs
• Methylenedioxymethamphetamine, also known
as MDMA or Ecstasy, is a synthetic mindaltering drug that exhibits many hallucinogenic
and amphetamine-like effects.
• Ecstasy enhances self-awareness and decreases
inhibitions, however, seizures, muscle
breakdown, stroke, kidney failure, and
cardiovascular system failure often accompany
chronic abuse.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-37
Club Drugs
• 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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
5-38
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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Anabolic Steroids
• Side effects include unpredictable effects on
mood and personality, depression, diminished
sex drive, halting bone growth, and liver
cancer.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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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.
– Screening test that is nonspecific and preliminary in
nature to reduce the possibilities to a manageable
number.
– Confirmation test that is a single test that
specifically identifies a substance.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Preliminary Analysis
• 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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Confirmational Determination
• Once this preliminary analysis is completed, a
confirmational 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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Mass Spectroscopy
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By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Infrared Spectroscopy
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Chromatography
• Chromatography is a means of separating and
tentatively identifying the components of a
mixture.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Chromatography
• 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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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TLC
• TLC uses a solid stationary phase usually
coated onto a glass plate and a mobile liquid
phase to separate the components of the
mixture.
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By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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TLC
• 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 known as the
Rf value.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Gas Chromatography
• In GC, the moving phase is actually a gas called
the carrier gas, which flows through a column.
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By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Gas Chromatography
• 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.
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©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Gas Chromatography
• 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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By Richard Saferstein
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Upper Saddle River, NJ 07458
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Spectrohotometry
• 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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By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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UVand 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.
FORENSIC SCIENCE: An Introduction, 2nd ed.
By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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UVand IR Spectrophotometry
• Different materials always have distinctively
different infrared spectra; each IR spectrum is
therefore equivalent to a “fingerprint” of that
substance.
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By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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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:
–
–
–
–
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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By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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Mass Spectrometry
• In the mass spectrometer, a beam of high-energy
electrons collide with a material, producing
positively charged ions.
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Mass Spectrometry
• 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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By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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GC and Mass
• 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.
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By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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GC and Mass
• 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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By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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GC and Mass
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Collection and Preservation
• The field investigator has the responsibility of
ensuring that the evidence is properly packaged
and labeled for the laboratory.
• Generally common sense is the best guide,
keeping in mind that the package must prevent
the loss of the contents and/or crosscontamination.
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By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
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Collection and Preservation
• Often the original container in which the drug
was seized will suffice.
• All packages must be marked with information
that is sufficient to ensure identification by the
officer in the future and establish the chain of
custody.
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By Richard Saferstein
©2011, 2008 Pearson Education, Inc.
Upper Saddle River, NJ 07458
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