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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.”

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Presentation on theme: "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.”"— Presentation transcript:

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 Chapter 7 Kendall/Hunt Publishing Company2 Drugs  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. Students will learn:

3 Chapter 7 Kendall/Hunt Publishing Company3 Drugs  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. Students will be able to:

4 Chapter 7 Kendall/Hunt Publishing Company4 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.

5 Chapter 7 Kendall/Hunt Publishing Company5 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.

6 Chapter 7 Kendall/Hunt Publishing Company6 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

7 Chapter 7 Kendall/Hunt Publishing Company7 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

8 Chapter 7 Kendall/Hunt Publishing Company8 Identification of Drugs  PDR—Physicians’ Desk Reference  Field Tests—presumptive tests  Laboratory Tests—conclusive tests

9 Chapter 7 Kendall/Hunt Publishing Company9 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

10 Chapter 7 Kendall/Hunt Publishing Company10 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.

11 Chapter 7 Kendall/Hunt Publishing Company11 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

12 Chapter 7 Kendall/Hunt Publishing Company12 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

13 Chapter 7 Kendall/Hunt Publishing Company13 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.

14 Chapter 7 Kendall/Hunt Publishing Company14 Types of Chromatography  Paper  Thin Layer (TLC)  Gas (GC)  Pyrolysis Gas (PGC)  Liquid (LC)  High Pressure Liquid (HPLC)  Column

15 Chapter 7 Kendall/Hunt Publishing Company15 Paper Chromatography  Stationary phase— paper  Mobile phase—a liquid solvent Capillary action moves the mobile phase through the stationary phase

16 Chapter 7 Kendall/Hunt Publishing Company16 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

17 Chapter 7 Kendall/Hunt Publishing Company17 Retention Factor (R f )  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 R f 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).

18 Chapter 7 Kendall/Hunt Publishing Company18 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 R f for the qualitative analysis

19 Chapter 7 Kendall/Hunt Publishing Company19 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).

20 Chapter 7 N. Ron Leigh Case While sitting quietly at his desk, N. Ron Leigh, an executive of a multinational energy company, was stricken with what appeared to be a severe allergic reaction. His throat swelled to such an extent that he could hardly breathe. Rapid and effective response to a 911 call saved his life. Both the paramedics and police wondered what brought on such a sudden attack.

21 Chapter 7 N. Ron Leigh Case - Facts ®A bottle of Tylenol was found on Mr. Leigh’s desk ®It was well known that Leigh suffered from asthma, bouts of sinusitis, and tension headaches. ®Several caplets from the Tylenol bottle have been submitted to your lab for analysis ®Were they in fact Tylenol or aspirin or ibuprofen (either of the later two could have caused an allergic reaction)?

22 Chapter 7 Lab Data – TLC Chromatography ®Ms. Scholle ran TLC of known Tylenol, aspirin, ibuprofen, and the pills found at the scene last night. ®The chromatogram was developed in class w/iodine pellets. ®Look at the resulting chromatogram and write down observations

23 Chapter 7 ®Use the following data to calculate the Rf for each of the samples… Lab Data – TLC Chromatography

24 Chapter 7 N. Ron Leigh Case ®A plasma sample taken from Mr. Leigh has been submitted to the lab for analysis. ®Did Mr. Leigh actually take aspirin? How much? ®Use handout and data to help you finish solving this mystery and write a summary report suitable for admission into a trial.

25 Chapter 7 Kendall/Hunt Publishing Company25 Spectroscopy  Spectroscopy—the interaction of electromagnetic radiation with matter.  Spectrophotometer—an instrument used to measure and record the absorption spectrum of a chemical substance.

26 Chapter 7 Kendall/Hunt Publishing Company26 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

27 Chapter 7 Kendall/Hunt Publishing Company27 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

28 Chapter 7 Kendall/Hunt Publishing Company28 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.

29 Chapter 7 Kendall/Hunt Publishing Company29 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.

30 Chapter 7 Kendall/Hunt Publishing Company30 Mass Spectra Each molecular species has its own unique mass spectrum.

31 Chapter 7 Kendall/Hunt Publishing Company31 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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