Chapter 7 Drugs

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Chapter 7Drugs

• Having sniffed the dead mans 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 Doyles
• A Study in Scarlet

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Drugs
Students will learn

• 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.

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Drugs
Students 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

• 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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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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Controlled Substances Act

• Schedule Ihigh potential for abuse no currently
  acceptable medical use in the US a lack of
  accepted safety for use under medical supervision
• Schedule IIhigh potential for abuse a currently
  accepted medical use with severe restrictions
  abuse may lead to severe psychological or
  physical dependence
• Schedule IIIlower 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 IVlow 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 Vlow 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

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Examples of Controlled Substances and Their
Schedule Placement

• Schedule Iheroin (diacetylmorphine), LSD,
  marijuana, ecstasy (MDMA)
• Schedule IIcocaine, morphine, amphetamines
  (including methamphetamines), PCP, Ritalin
• Schedule IIIintermediate acting barbiturates,
  anabolic steroids, ketamine
• Schedule IVother stimulants and depressants
  including Valium, Xanan, Librium, phenobarbital,
  Darvon
• Schedule Vcodeine found in low doses in cough
  medicines

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Controlled Drugs

• Hallucinogens
• Stimulants
• Narcotics
• Depressants

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LSD
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Cocaine
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Crack Cocaine
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Marijuana
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Meth Supplies
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Meth Affects
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Identification of Drugs

• PDRPhysicians Desk Reference
• Field Testspresumptive tests
• Laboratory Testsconclusive tests

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Human ComponentsUsed for Drug Analysis

• Blood
• Urine
• Hair
• Gastric Contents
• Bile

• Liver tissue
• Brain tissue
• Kidney tissue
• Spleen tissue
• Vitreous Humor of the Eye

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Physicians Desk Reference

• PDRa 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.

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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

• Confirmatory tests
• Spectrophotometry
• Ultraviolet (UV)
• Visible
• Infrared (IR)
• Mass spectrometry

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Presumptive Color Tests

• Marquisturns purple in the presence of most
  opium derivatives and orange-brown with
  amphetamines
• Dillie-Koppanyiturns violet-blue in the presence
  of barbiturates
• Duquenois-Levineturns a purple color in the
  presence of marijuana
• Van Urkturns a blue-purple in the presence of
  LSD
• Scott testcolor test for cocaine, blue

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Chromatography

• A technique for separating mixtures into their
  components
• Includes two phasesa 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 Pressure Liquid (HPLC)
• Column

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Paper Chromatography

• Stationary phasepaper
• Mobile phasea 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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Gas Chromatography

• Phases
• Stationarya solid or a viscous liquid that lines
  a tube or column
• Mobilean 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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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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Spectroscopy

• Spectroscopythe interaction of electromagnetic
  radiation with matter.
• Spectrophotometeran instrument used to measure
  and record the absorption spectrum of a chemical
  substance.

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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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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.
• Resultan absorption or transmittance spectrum
• Gives a unique view of the substance like a
  fingerprint

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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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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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Mass Spectra

• Each molecular species has its own unique mass
  spectrum.

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IR Spectrophotometry andMass 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 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.

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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.