1. 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

2. Kendall/Hunt Publishing Company
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.
Kendall/Hunt Publishing Company

3. Kendall/Hunt Publishing Company
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.
Kendall/Hunt Publishing Company

4. Kendall/Hunt Publishing Company
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.
Kendall/Hunt Publishing Company

5. 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.
Kendall/Hunt Publishing Company

6. Controlled Substances Act
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

7. 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
Kendall/Hunt Publishing Company

8. Identification of Drugs
PDR—Physicians’ Desk Reference
Field Tests—presumptive tests
Laboratory Tests—conclusive tests
Kendall/Hunt Publishing Company

9. Human Components Used for Drug Analysis
Blood
Urine
Hair
Gastric Contents
Bile
Liver tissue
Brain tissue
Kidney tissue
Spleen tissue
Vitreous Humor of the Eye
Kendall/Hunt Publishing Company

10. 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.
Kendall/Hunt Publishing Company

11. Drug Identification Screening or presumptive tests Confirmatory 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
Kendall/Hunt Publishing Company

12. Presumptive Color Tests
Marquis—turns purple in the presence of most opium derivatives and orange-brown with amphetamines
Dillie-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
Kendall/Hunt Publishing Company

13. 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.
Kendall/Hunt Publishing Company

14. Types of Chromatography
Paper
Thin Layer (TLC)
Gas (GC)
Pyrolysis Gas (PGC)
Liquid (LC)
High Pressure Liquid (HPLC)
Column
Kendall/Hunt Publishing Company

15. Kendall/Hunt Publishing Company
Paper Chromatography
Stationary phase— paper
Mobile phase—a liquid solvent
Capillary action moves the mobile phase through the stationary phase
Kendall/Hunt Publishing Company

16. 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
Kendall/Hunt Publishing Company

17. Kendall/Hunt Publishing Company
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).
Kendall/Hunt Publishing Company

18. 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
Kendall/Hunt Publishing Company

19. 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).
Kendall/Hunt Publishing Company

20. Kendall/Hunt Publishing Company
Spectroscopy
Spectroscopy—the interaction of electromagnetic radiation with matter.
Spectrophotometer—an instrument used to measure and record the absorption spectrum of a chemical substance.
Kendall/Hunt Publishing Company

21. 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
Kendall/Hunt Publishing Company

22. Kendall/Hunt Publishing Company
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
Kendall/Hunt Publishing Company

23. Kendall/Hunt Publishing Company
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.
Kendall/Hunt Publishing Company

24. 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.
Kendall/Hunt Publishing Company

25. Kendall/Hunt Publishing Company
Mass Spectra
Each molecular species has its own unique mass spectrum.
Kendall/Hunt Publishing Company

26. 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
Kendall/Hunt Publishing Company