Transcript Drug Identification, continued

Drugs
Drugs
Objectives
You will understand:
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, overthe-counter medications, and illegal
drugs.
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Drugs
Objectives, continued
You will be able to:
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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Drugs
Objectives, continued
You will be able to:
Describe IR, UV-VIS spectroscopy, and GCMS.
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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Drugs
Drugs and Crime
® A drug is a natural or synthetic substance designed to affect the
subject psychologically or physiologically.
® Any drugs taken in excessive amounts and causes illness or death is
classified as a poison
® Legal drugs that are taken solely for pleasure are considered illicit
drugs.
® “Controlled substances” are drugs that are restricted by law.
® The Controlled Substances Act is a law that was enacted in 1970; it
lists illegal drugs, their categories, and penalties for possession, sale,
or use.
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Drugs
Illegal or Illicit?
An illegal drug is a drug that is against the law to have, use, or
distribute.
An illicit drug is a legal drug used in an inappropriate or illegal way.
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Controlled Substances Act
Schedule I—high potential for abuse; no currently accepted medical
use in the U.S.; a lack of accepted safety for use under medical
supervision
Examples: heroin (diacetylmorphine), LSD, marijuana, ecstasy (MDMA)
Schedule II—high potential for abuse; a currently
accepted medical use with severe restrictions; abuse
may lead to severe psychological or physical
dependence
Examples: cocaine, morphine, amphetamines (including
methamphetamines), PCP, Ritalin
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Drugs
Controlled Substances Act, continued
Schedule III—lower potential for abuse than the drugs in I or II; a
currently accepted medical use in the U.S.; abuse may lead to
moderate physical dependence or high psychological dependence
Examples: intermediate-acting barbiturates, anabolic steroids, ketamine
Schedule IV—low potential for abuse relative to drugs in III; a
currently accepted medical use in the U.S.; abuse may lead to
limited physical or psychological dependence relative to drugs
in III
Examples: stimulants and depressants including Valium, Xanax,
Librium, phenobarbital, Darvon
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Drugs
Controlled Substances Act, continued
Schedule V—low potential for abuse relative to drugs in IV; currently
accepted medical use in the U.S.; abuse may lead to limited physical
or psychological dependence relative to drugs in IV
Examples: codeine found in low doses in cough medicines
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Drugs
Classification for illicit drugs based on
pharmacological effects
®Hallucinogens: mostly naturally occurring
substances that can change normal thought
processes, perceptions, and moods.
®Examples: Marijuana, LSD, PCP, Ecstasy,
Ketamine
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Drugs
Classification for illicit drugs based on
pharmacological effects
®Stimulants: acts on the central nervous system
(CNS) to increase alertness, energy while
suppressing appetite and fatigue.
®Examples: cocaine, caffeine, amphetamines,
metamphetamines
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Drugs
Classification for illicit drugs based on
pharmacological effects
®Narcotics: Analgesics substances which act on
the CNS to relieve pain.
®Examples: codeine, heroin, opium, oxycodon,
fentanyl
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Drugs
Classification for illicit drugs based on
pharmacological effects
®Depressants: Acts on the CNS and results in
calming the user and slower his/her response
to stimuli.
®Examples: barbituates, alcohol, valium
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Drugs
Drug analysis and Identification
® 75 % of evidence being examined by forensic
scientist in the U.S. is considered drug related
®Forensic scientists have many test for
identifying drugs and poison
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Drugs
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 and states
whether it is prescription, over-the-counter, or a
controlled substance; it gives more detailed information
about the drug as well.
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Drugs
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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Drugs
Drug Identification
Screening or presumptive tests
Confirmatory tests
Spot or color tests
Spectrophotometry
Microcrystalline test—
• Ultraviolet (UV)
a reagent is added, producing a
crystalline precipitate that is unique for
a certain drug
• Visible
• Infrared (IR)
Mass spectrometry
Chromatography
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Drugs
Drug Identification, continued
Screening or presumptive tests only tell that the drug is possibly present.
Confirmatory tests tell that the drug is positively present.
(Screening tests are easier, cheaper, and quicker to use.)
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Drugs
Presumptive Color Tests
Marquis—turns purple in the presence of
most opium derivatives and orange-brown
with amphetamines
Dille-Koppanyi—turns violet-blue 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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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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Types of Chromatography
Paper
Thin-layer (TLC)
Gas (GC)
Pyrolysis gas (PGC)
Liquid (LC)
High-performance liquid (HPLC)
Column
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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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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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Retention Factor (Rf)
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).
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Drugs
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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Drugs
Uses of Gas Chromatography
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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Drugs
Confirmatory Tests: 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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Spectrophotometry
Types
Ultraviolet
Visible
Infrared
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Drugs
Infrared Spectrometry
Material absorbs energy in the near-IR region of the electromagnetic
spectrum
Compares the IR light beam before and after it passes through a
transparent sample
Result—an absorption or transmittance spectrum
Gives a unique view of the substance; like a fingerprint
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Mass Spectrometry, continued
®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 positivecharged fragments. These are sorted and collected according to their
mass-to-charge ratio by an oscillating electric or magnetic field.
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Mass Spectra
Each molecular species has its own unique mass spectrum.
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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.
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People of Historical Significance
Arthur Jeffrey Dempster was born in Canada, but studied at 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 and established
the basic theory and design of mass spectrometers that is still used to
this day.
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Drugs
Drugs
®What is a drug?
®List the different categories into which drugs
may be classified based on their
pharmaceutical effects
®List as many drugs as you can think of that fall
into each category
®What is the most commonly abused drug
®Approximately how much does the U.S. spend
each year to fight drug trafficking
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