Drugs
Drugs
2
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, over-the-counter medications, and illegal drugs.
Objectives
Drugs
3
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.
Objectives, continued
Drugs
4
You will be able to:
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.
Objectives, continued
Drugs
5
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.
Drugs
6
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.
Drugs
7
Controlled Substances ActSchedule 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
Drugs
8
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 IIIExamples: stimulants and depressants including Valium, Xanax, Librium, phenobarbital, Darvon
Drugs
9
Controlled Substances Act, continuedSchedule 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
Drugs
10
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
Drugs
11
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
Drugs
12
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
Drugs
13
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
Drugs
14
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
Drugs
15
Physicians’ Desk ReferencePDR—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.
Drugs
16
Human Components Used for Drug AnalysisBlood
Urine
Hair
Gastric contents
Bile
Liver tissue
Brain tissue
Kidney tissue
Spleen tissue
Vitreous humor of the eye
Drugs
17
Drug IdentificationScreening or presumptive tests
Spot or color tests
Microcrystalline test—
a reagent is added, producing a crystalline precipitate that is unique for a certain drug
Chromatography
Confirmatory tests
Spectrophotometry
• Ultraviolet (UV)
• Visible
• Infrared (IR)
Mass spectrometry
Drugs
18
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.)
Drug Identification, continued
Drugs
19
Presumptive Color TestsMarquis—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
Drugs
20
ChromatographyA 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
Drugs
21
Types of ChromatographyPaper
Thin-layer (TLC)
Gas (GC)
Pyrolysis gas (PGC)
Liquid (LC)
High-performance liquid (HPLC)
Column
Drugs
22
Paper ChromatographyStationary phase—paper
Mobile phase—a liquid solvent
Capillary action moves the mobile
phase through the stationary phase.
Drugs
23
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
Drugs
24
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).
Drugs
25
Gas ChromatographyPhases
Stationary—a solid or a viscous liquid that lines a tube or column
Mobile—an inert gas like nitrogen or helium
AnalysisShows a peak that is proportional to the quantity of the substance present
Uses retention time instead of Rf
for the qualitative analysis
Drugs
26
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.)
Drugs
27
Confirmatory Tests: SpectroscopySpectroscopy—the interaction of electromagnetic radiation with
matter
Spectrophotometer—an instrument used to measure and record the absorption spectrum of a chemical substance
Drugs
28
Spectrophotometry
Types
Ultraviolet
Visible
Infrared
Drugs
29
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
Drugs
30
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 positive-charged fragments. These are sorted and collected according to their mass-to-charge ratio by an oscillating electric or magnetic field.
Drugs
31
Mass Spectra
Each molecular species has its own unique mass spectrum.
Drugs
32
IR Spectrophotometry and Mass SpectrometryBoth work well in identifying pure substances.
Mixtures are difficult to identify in both techniques.
Both are compared to a catalog of knowns.
Drugs
33
People of Historical SignificanceArthur 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.
Drugs
34
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