Transcript Introduction to Forensic Science

Narcotic Drugs
 Pharmacologically classified as an
analgesic
 Central Nervous System
Depressants
 Popular drugs – heroin,
morphine, codeine, methadone and
propoxyphene
Hallucinogens
 Marijuana
 Derived from the plant Cannabis
 Hashish – concentrated
 Sinsemilla – unfertilized flowering tops
of the female Cannabis plant
 Active ingredient is THC
 Potency is normally 4-5%
 Simsemilla averages 6-12%
 Liquid hashish averages 8-22%
 Potential medical uses
Hallucinogens
 LSD – derived from ergot, a fungus of certain grains and
grasses
 Powerful drug
 Visual hallucinations, changes in moods, anxiety, tension, etc
 Flashbacks possible
 Phencyclidine – PCP
 Human response unpredictable
 Dangerous drug – paranoia and violence possible
 Schizophrenic behavior possible days after use
 Methylenedioxymethamphetamine (aka MDMA or ecstasy)
 Originally patented as appetite suppressant
 Severe adverse reactions, including fatal side effects
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Depressants
Alcohol (aka ethanol, ethyl alcohol, booze, etc.)
 Central nervous system depressant
 Legalized and most widely used drug
 A common effect is impairment
 Legal blood alcohol level in Oklahoma
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is 0.10%, or 100 mg/dL
Barbiturates
 All are derivatives of barbituric acid
 Big 5: amobarbital, secobarbital, phenobarbital, pentobarbital and
butalbital
Methaqualon
. Tranquilizers
 Major players: reserpine, chlorpromazine, meprobamate,
chlordiazepoxide, diazepam
Inhalants
 Volatile organic solvents – toluene, naphtha, gasoline among others
 Initial exhilaration and euphoria followed by impaired judgment,
drowsiness and stupor
 Danger of liver, heart and brain damage
Stimulants
 Amphetamines
 Initial feeling of well-being and alertness followed by
fatigue and a loss of appetite
 Amphetamine, methamphetamine and “ice” (crystal meth)
are favorites
 Phenmetrazine and phendimetrazine have similar properties
 Cocaine
 First used medically by Freud in Europe
 Medical use is now limited
 Extracted from the leaves of coca plant (Erythroxylon coca)
 “Crack” cocaine is the drug of choice
 Cocaine produces the strongest psychological compulsions
for continued use
Drugs: Organized by Control Laws
 Federal law restricting the manufacture and distribution of dangerous substances
 The U.S. Attorney General has the authority to change the schedules
 The criminal penalties associated with this law are greatest with schedules I and II.
Controlled Substances Act
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Schedule I
 No medical use
 High potential for abuse
 Heroin, LSD, methaqualone and marijuana High potential for abuse
 Cocaine, opiates, PCP, amphetamines, methadone and fast-acting barbiturates
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Schedule II
 Accepted medical use
 Potential for psychological or physical dependence
 Cocaine, opiates, PCP, amphetamines, methadone and fast-acting barbiturates
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Schedule III
 Less potential for abuse than schedules I and II
 Currently accepted medical use
 Potential for low or moderate physical dependence or high psychological dependence
 Anabolic steroids, some codeine preparations and some barbiturate preparations (phenobarbital not included)
Controlled Substances Act
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Schedule IV
 Low potential for abuse relative to schedule III drugs
 Currently accepted medical use
 Relatively low limited dependence risk
 Propoxyphene, phenobarbital, meprobamate, diazepam and chlordiazepoxide
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Schedule V
 Low abuse potential
 Medical use
 Less potential for producing dependency
 Certain opiate drug mixtures that contain non-narcotic medicinal ingredients
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Designer drugs
 Can be placed under schedule I
 Fentanyl analogues
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Control of chemical precursors
 Example – precursors to amphetamine, methamphetamine and PCP are controlled as schedule II substances
Drugs: Organized by Chemistry
 Extraction, Separation and isolation
 Liquid-Liquid
 TLC
 HPLC
 Characterization
 Color tests - often termed presumptive tests
 Marquis – purple color in presence of opiates and orange-brown in presence of
amphetamines
 Dillie-Koppanyi – violet-blue color in presence of barbiturates
 Duquenois-Levine – purple color in presence of marijuana
 Van Urk – blue-purple color in presence of LSD
 Scott – blue color in presence of cocaine
 Characterization
 UV and IR Spectroscopy
 GC-MS
 Note that the neutral classification includes
thosedrugs that have no ionizable center and those
which are amphoteric
 Alkaloids are generally derived from plants ehile the
nonalkaloids are syhtthetic or semisynthetic
Methyl Salicylate - Aspirin
pKa = 3.5
Dia(acetyl)morphine - opiod,
active ingredient in heroin
pKa = 8
Morphine
amphoteric
Problem#1
Problem#2
Problem#3
Problem#3
Problem#3
HPLC Separation of Methamphetamines
Column: C8, 4.6 x 150 mm
Mobile Phase:
85% 25 mM phosphate buffer
15% ACN
Flow Rate: 1.0 mL/min
Temperature: 35°C
Detection: 254 nm
Sample: Amphetamines
1. Phenylpropanolamine
2. Ephedrine
3.Amphetamine
4. Methamphetamine
5. Phenteramine
pKa
9.4
9.6
9.9
10.1
10.1
Problems; Bell page 128
5. Aspirin (acetylsalicylic acid) has a of 3.5. The pH of the stomach is approximately 1,
while the pH of the intestines is approximately 6. Calculate the fraction of aspirin that is
ionized in each area (show your work), and
use the results to predict where the drug is preferentially absorbed.
6. Repeat the calculation in Question 5 for caffeine, a weak base with a of 0.6.
7. Diazepam tablets are supplied in 2-, 5-, and 10-mg increments. Suppose several tablets
are received in a laboratory as evidence and, using the Physician’s Desk
Reference, an analyst was able to tentatively identify them as Valium®, 10 mg. Suppose
further that you learn that the tablets also contain anhydrous lactose,
starches, dyes, and calcium stearate. Describe a method for isolating the active ingredient
from fillers, using a LLE scheme. Justify and explain each step of
the method.
8. Quinine is a dibasic molecule with of 5.1 and 9.7. It is encountered as a diluent (cutting
agent) for heroin. To extract quinine from an aqueous solution, what pH should be used
and why?
9. Devise a solvent extraction method that could be used to separate a mixture of
powdered sugar, cornstarch, cocaine, and amphetamine. Justify each step and separation.