5-1 prentice hall ©2008 pearson education, inc. upper saddle river, nj 07458 drugs chapter 5
TRANSCRIPT
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PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458
DRUGS
Chapter 5
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PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458
Introduction• Drug - a natural or synthetic substance that
produces physiological or psychological effects in humans or other animals.
• 75% of all evidence being processed in crime labs is related to illegal drugs
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DEA – NJ Drug StatisticsNJ State Facts (http://www.justice.gov/dea/pubs/state_factsheets/newjersey.html)
• Population: 8,717,925• State Prison Population: 26,757• Probation Population: 143,315 • Violent Crime Rate National Ranking: 26
2010 Federal Drug Seizures• Cocaine: 900.78 kg• Heroin: 140.21 kg• Methamphetamine: 47.94 kg/26 DU• Marijuana: 2,887.80kg• Hashish: 57.55 kg.• MDMA: 3,790 DU• Meth Lab Incidents: 3 (DEA, state, and local)
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Narcotics• Narcotics - drugs that
induce sleep and relieve pain
Lowers blood pressure and slows breathing rate
Examples:- Heroin- Morphine - Codeine
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Hallucinogens• Hallucinogens include marijuana, LSD,
PCP, and MDMA (Ecstasy)• PCP 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 substances
used to slow down the functions of the central nervous system.
• Depressants calm irritability and anxiety and may induce sleep.
• Examples: - alcohol - Xanax
-Rohypnol - Barbiturates
“Roofies”-tranquilizers
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Stimulants• Stimulants – substance that speeds up, or
stimulates, the central nervous system• Stimulants give the user an adrenaline rush often
followed by a crash. • Heavy use of stimulants result in paranoia,
restlessness, irritability, and depression.
• The most frequently used stimulant is coffee with caffeine.
• The most common illegal stimulants are cocaine and amphetamines.
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Amphetamines• A group of synthetic stimulants that
are usually called UPPERS or SPEED.
• Used in diet pills• Hydroxycut with Ephedra
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COCAINE• Erythroxoylon coca – the plant• Increases alertness and energy• Suppression of hunger, fatigue, and
boredom
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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 based on the drug’s– potential for abuse– potential for physical and psychological dependence– medical use/value
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Your Brain on Drugs• Youtube - https://www.youtube.com/
watch?v=N6NL41bREHo
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• A forensic chemist will determine if a unknown substance is a drug by performing a series of tests
• The results will have a direct bearing on the process of determining the guilt or innocence of a defendant.
Forensic Drug Analysis
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Drug Identification
2-step procedure:
1) Use screening tests to reduce the number of possibilities to a small and manageable number.
2) Use more sophisticated tests to pinpoint and confirm the identity of the drug.
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Drug Identification
Screening tests
• Color tests
• Microcrystalline test
• Chromatography
Confirmatory tests
• Spectrophotometry
Ultraviolet (UV) Visible Infrared (IR)
• Mass spectrometry
Screening tests only tells what drug is possibly present. (Screening tests are easier, cheaper, and quicker to use.)
Confirmatory tests tell that the drug is definitely present.
Video – Drug Analysis
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Screening tests• Color Tests (5 tests) - Suspect material is
subjected to a series of different color tests that will produce characteristic colors for the more common illicit drugs.
• Microcrystalline Test
Forensic Drug Analysis
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5 Color Tests1. Marquis
– turns purple when positive for heroin and morphine
– turns orange-brown when positive for amphetamines and methamphetamines.
2. Dille-Koppanyi – tests for barbiturates
3. Duqenois-Levine – series of chemicals to test for marijuana
4. Van Urk –tests for LSD
5. Scott – three solution test for the presence of cocaine. Positive color sequence is blue-pink-blue.
Video - https://www.youtube.com/watch?v=ue9zp5P2Mxo
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Microcrystalline Tests
• Microcrystalline tests - used to identify specific drug substances by studying the size and shape of crystals formed
Cocaine crystal – “K” shaped methamphetamine crystal
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Confirmation Determination• 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 (GCMS) is used to specifically identify a drug substance.
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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 Pressure 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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Calculating Rf Values• The distance moved by a pigment is
compared to the distance moved by the solvent front. We call this relationship the retention time or Rf value and define it as follows:
Rf = Distance moved by the pigment
Distance from pigment origin to solvent front
• Paper chromatography can be used to
identify substances both qualitatively (by color) and quantitatively by its characteristic Rf value.
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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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Gas ChromatographyIn GC, the moving phase is actually a gas called the carrier gas, which flows through a column.
Phases Stationary —liquid that lines a
tube or column Mobile — a gas like nitrogen or
helium
• After a mixture passes through the length of the column, it will become separated into its components.
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Gas Chromatography Results• Chromatogram: The printed record of the separation. • Retention Time: The time required for a component to
come out of a GC column.
Analysis Shows a peak that
is proportional to the quantity of the substance present
Uses retention time instead of Rf for the qualitative analysis
https://www.youtube.com/watch?v=4Xaa9WdXVTM
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Uses of Gas Chromatography
Not considered a confirmation of a controlled substance
For more accurate results – Used in conjunction with mass spectroscopy (MS) and infrared spectroscopy (IR) a separation tool for MS and IR
Used to quantitatively measure the concentration of a sample.
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Marijuana Testing The U.S. Drug Enforcement
Administration (DEA) regulates
marijuana under the Controlled
Substances Act (CSA).
substances. Within this CSA
framework, marijuana is placed
into Schedule 1. Many testing
methods are used for detecting
THC in saliva: radio
immunoassay (RIA) method, gas
chromatography with electron
capture detection (GC-ECD),
and liquid chromatography with
electrochemical detection.
Gas chromatography-mass spectrometry (GC-MS) is the preferred method for analysis - screening and confirmation in one step.3 GC/MS is extremely selective and sensitive, enabling routine analysis of THC in saliva at the low levels required by most regulatory bodies.Testing for prosecution is actively pursued EVERYDAY.REMEMBER: Marijuana is still considered a Schedule I drug by the U.S. Government - federal laws trump state or local laws.Source: Forensic Magazine 23-29 10-17-2010
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Spectrophotometry Spectrophotometry - measures the quantity of
radiation that a particular material (i.e. drug) absorbs
Spectrophotometer—an instrument used to measure the quantity of radiation absorbed by material
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Infrared Spectrophotometry
Mass Spectrometry
Types
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Infrared (IR) Spectrometry
Material absorbs energy in the near-Infrared (IR) region of the electromagnetic spectrum.
Result—an absorption spectrum Gives a unique view of the substance; like a
fingerprint used to determine the identify of an unknown substance
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Mass Spectrometry• In the mass spectrometer, a beam
of high-energy electrons collide with a sample, producing positively charged ions.
• These positive ions almost instantaneously decompose into numerous fragments
Fragments of sample are separated according to their masses.
• The unique feature of mass spectrometry is that under carefully controlled conditions, no two substances produce the same fragment pattern.
Video
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Do Now• How does Infrared spectrophotometry
identify a specific drug?• What technique measures the amount of a
drug?
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Mass Spectrometry• Gas chromatography (GC) and mass spec have
major drawbacks, GC does not give a specific identification. Mass spectrometry cannot separate mixtures or provide specific identification.
• By combining gas chromatography and mass spectrometry, constituents of mixtures can be specifically identified.
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GC and Mass• The GC column and the mass spectrometer
can be connected to one another.
• The separation of a mixture’s components is first accomplished by the GC.
• Then, fragmentation of each separated component by high-energy electrons in the mass spectrometer, will produce a distinct pattern, or a “fingerprint” of the sample being examined.
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Collection and Preservation• The evidence must be properly packaged and
labeled for the laboratory.• The original container in which the drug was
seized will be sufficient.• All samples must be marked with information
that will ensure identification in the future and establish the chain of custody.
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ChromatographyChromatography is a means of separating and identifying the components of a mixture. • Theory of chromatography is
that chemical substances partially escape into the surrounding environment when dissolved in a liquid or when absorbed on a solid surface.
• 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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Qualitative vs. Quantitative• Analytical techniques must give either a
qualitative or a quantitative result.
Qualitative gives only the identity of the suspect material.
Quantitative gives the percent composition of the different elements in a mixture.
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PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458
ChromatographyChromatography is a means of separating and identifying the components of a mixture. • Theory of chromatography is
that chemical substances partially escape into the surrounding environment when dissolved in a liquid or when absorbed on a solid surface.
• 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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TLCSolid stationary phase (usually coated onto a glass plate) and amobile liquid phase to separate the components of the mixture. • The liquid will move up the
plate by capillary action. • The sample travels between
the stationary phase (plate) and the moving liquid phase.
• Most compounds are colorless so results must be viewed by placing the plates under UV light or spraying the plate with a chemical reagent.
• The distance a spot travels up a thin-layer plate can be measured as a numerical value or the Rf value.
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SpectrophotometrySpectrophotometry measures the quantity of radiation that a particular material absorbs as a function of wavelength and frequency.
• Beer’s Law:The quantity of light absorbed at any frequency is directly proportional to the concentration of the absorbing substance.
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UVand IR Spectrophotometry• Most forensic laboratories use
UV and IR spectrophotometers to identify chemical compounds.
• The UV spectrum is simple enough to determine the general identity of an unknown substance.
• The IR spectrum is much more exact; each IR spectrum is equivalent to a “fingerprint” of that substance.
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The Spectrophotometer• Measures the light 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
• The light source can be the visible, ultraviolet (UV) or infrared (IR)
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GC and Mass• The GC column and the mass
spectrometer can be connected. • The separation of a mixture’s components
is first accomplished by the GC.• Then, fragmentation of each separated
component by high-energy electrons in the mass spectrometer, will produce a distinct pattern, or a “fingerprint” of the sample being examined.
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Collection and Preservation• The evidence must be properly packaged and
labeled for the laboratory.• Common sense is the best guide, the package
must prevent the loss of the sample contents and/or cross-contamination with another sample.
• The original container in which the drug was seized will be suffcient.
• All samples must be marked with information that will ensure identification in the future and establish the chain of custody.