Chapter 7
Drugs
“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
Drugs
Students will learn:




Chapter 7
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.
Kendall/Hunt Publishing Company
1
Drugs
Students will be able to:




Chapter 7
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.
Kendall/Hunt Publishing Company
2
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.
Chapter 7
Kendall/Hunt Publishing Company
3
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.
Chapter 7
Kendall/Hunt Publishing Company
4
Controlled Substances Act





Chapter 7
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
Kendall/Hunt Publishing Company
5
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
Chapter 7
Kendall/Hunt Publishing Company
6
Controlled Drugs
®Hallucinogens
®Stimulants
®Narcotics
®Depressants
Chapter 7
Kendall/Hunt Publishing Company
7
LSD
Chapter 7
Kendall/Hunt Publishing Company
8
Cocaine
Chapter 7
Kendall/Hunt Publishing Company
9
Crack Cocaine
Chapter 7
Kendall/Hunt Publishing Company
10
Marijuana
Chapter 7
Kendall/Hunt Publishing Company
11
Meth Supplies
Chapter 7
Kendall/Hunt Publishing Company
12
Meth Affects
Chapter 7
Kendall/Hunt Publishing Company
13
Identification of Drugs
 PDR—Physicians’ Desk Reference
 Field Tests—presumptive tests
 Laboratory Tests—conclusive
tests
Chapter 7
Kendall/Hunt Publishing Company
14
Human Components
Used for Drug Analysis
Chapter 7
 Blood
 Liver tissue
 Urine
 Brain tissue
 Hair
 Kidney tissue
 Gastric Contents
 Spleen tissue
 Bile
 Vitreous Humor of
the Eye
Kendall/Hunt Publishing Company
15
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.
Chapter 7
Kendall/Hunt Publishing Company
16
Drug Identification
Screening or
presumptive tests
 Spot or color tests
 Microcrystalline test—
a reagent is added
that produces a
crystalline precipitate
which is unique for a
certain drug.
 Chromatography
Chapter 7
Confirmatory tests
 Spectrophotometry
 Ultraviolet (UV)
 Visible
 Infrared (IR)
 Mass spectrometry
Kendall/Hunt Publishing Company
17
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
Chapter 7
Kendall/Hunt Publishing Company
18
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.
Chapter 7
Kendall/Hunt Publishing Company
19
Types of Chromatography







Chapter 7
Paper
Thin Layer (TLC)
Gas (GC)
Pyrolysis Gas (PGC)
Liquid (LC)
High Pressure Liquid (HPLC)
Column
Kendall/Hunt Publishing Company
20
Paper Chromatography
 Stationary phase—
paper
 Mobile phase—a liquid
solvent
Capillary action moves
the mobile phase
through the stationary
phase
Chapter 7
Kendall/Hunt Publishing Company
21
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
Chapter 7
Kendall/Hunt Publishing Company
22
Retention Factor (Rf)



Chapter 7
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).
Kendall/Hunt Publishing Company
23
Gas Chromatography
Phases
 Stationary—a solid or a
viscous liquid that lines a
tube or column
 Mobile—an inert gas like
nitrogen or helium
Chapter 7
Analysis
 Shows a peak that is
proportional to the
quantity of the
substance present
 Uses retention time
instead of Rf for the
qualitative analysis
Kendall/Hunt Publishing Company
24
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).
Chapter 7
Kendall/Hunt Publishing Company
25
Spectroscopy
 Spectroscopy—the interaction of
electromagnetic radiation with matter.
 Spectrophotometer—an instrument used to
measure and record the absorption spectrum of
a chemical substance.
Chapter 7
Kendall/Hunt Publishing Company
26
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
Chapter 7
Kendall/Hunt Publishing Company
27
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
Chapter 7
Kendall/Hunt Publishing Company
28
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.
Chapter 7
Kendall/Hunt Publishing Company
29
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.
Chapter 7
Kendall/Hunt Publishing Company
30
Mass Spectra
Each molecular species has its own
unique mass spectrum.
Chapter 7
Kendall/Hunt Publishing Company
31
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
Chapter 7
Kendall/Hunt Publishing Company
32
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.
Chapter 7
Kendall/Hunt Publishing Company
33
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.
Chapter 7
Kendall/Hunt Publishing Company
34