Transcript AJ 113: Forensic Chemistry: Drugs

JS 112: Forensic Chemistry: Drugs/Tox
I.
Pre Class Activities
a. Announcements and Assignments
II. Learning objectives
a.
b.
c.
d.
e.
f.
g.
Drugs- What is a drug?
Define psychological and physical dependence
Name and classify commonly abused drugs
Describe tendency to develop psychological and physical dependency
for the more commonly abused drugs
Describe the schedules of Controlled Substances Act
Describe lab tests that forensic chemists normally rely upon to
comprise a routine drug id scheme
Discuss the proper collection and preservation of drug evidence
Web links toxicology: http://home.lightspeed.net/~abarbour/vlibft.html
Assignments
a.
Assignments:
a. Read Chapters 8 and 9- Drugs and Toxicology for weds.
b. Read Chapters 10 and 12 Bloodstains and Serology for mon.
a. Extra credit:Due Monday 19 April
a. Find 1 article on alcohol abuse leading to a fatality e.g. DUI from a news
story within the last 3 months.
b. Write a 300 word summary and 3 questions and 3 answers on the article. Be
prepared to discuss it in class.
b. Bring Lab books with Reports Wedsc. Study for quiz for Monday 19 April on Drugs, Dr. Orrego Lecture and
Blood reading.
What is a Drug?
• A drug is a natural or synthetic substance
that is used to produce physiological or
psychological effects in humans or other
higher order animals
Drug Dependence
• Psychological dependence- The conditioned
use of a drug caused by underlying
emotional needs.
• Physical dependence- Physiological need
for a drug that has been brought about by its
regular use. Dependence is characterized by
withdrawal sickness when administration of
the drug is abruptly stopped.
Some Typical Drugs
Marijuana
Heroin
Cocaine
Potential of commonly abused drugs to produce
dependency with regular use
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Drug
Psychological
Narcotics
– Morphine
High
– Heroin
High
– Methadone
High
– Codeine
Low
Depressants
– Barbiturates (short-acting)High
– Barbiturates (long-acting)Low
– Alcohol
High
– Diazepam (Valium)
Moderate
Stimulants
– Amphetamines
High
– Cocaine
High
– Caffeine
Low
– Nicotine
High
Hallucinogens
– Marijuana
Low
– LSD
Low
– PCP
High
Physical
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
?
No
No (?)
Yes
No
No
No
Factors influencing control
• Individual, social, cultural, legal, and medical
• Weigh the beneficial aspects of the drug vs harm
the abuse will do to the individual and society
• Prohibition of alcohol led to disastrous failure
leading to the current debate over legalizing
marijuana- Balance between individual desires and
needs and society’s concern with the consequences
of drug abuse.
Narcotic Drugs
• Narcotic- Analgesic or pain-killing substance that
depresses vital body functions such as blood pressure,
pulse rate, and breathing rate. The regular administration
of narcotics will produce physical dependence.
• Analgesic- A drug or substance that lessens or eliminates
pain.
• Opium derivatives: Morphine, Heroin, Codeine derived
from opium.
• Opiates- not derived from opium but similar
physiological effects
– OxyContin – oxycodon for chronic pain- abused by 250,000!
– Methadone- quelled addict desire for heroine. Now used for
pain relief and is abused increasingly
Hallucinogens
Hallucinogen- A substance that induces changes in mood,
attitude, thought, or perception.
Examples:
Marijuana- Cannabis sativa L.: most widely used illicit
drug US
Hashish- sticky resin secretion extracted by soaking
in a solvent such as alcohol
Sensemilla-potent form of marijuana- unfertilized
flowering tops of female Cannabis plant
43 million tried it, 50% addicted
Hallucinogens- Marijuana
3000 years
2737 BC Emperor Shen Nung
1000 BC Hindu- India
500AD Persia and Arabia
1929 into US via Mexico
1964 discover tetrahydrocannabinol is
the substance responsible for
hallucinogenic property
Hallucinogens- Marijuana
• Increased sense of well being
• Dreamy carefree state
• Vivid sense of touch, sight, smell, taste,
sound
• Hunger
• Craving sweets
• Not noticeably different from normal state
Other Hallucinogens
• Lysergic acid diethylamide- LSD- derived from
fungus ergot attacking grasses: Potent 25 ug lasts
12 hours
• Mescaline
• Phencyclidine (PCP)-clan labs: 1-6mg feelings of
strength, and detachment. Soon unresponsive,
confused and agitated… paranoia and depression
• Psilocybin
• Methylenedioxymethamphetamine- MDMA or
ecstasy
Depressants
• Depressant- a substance used to depress the functions of the central
nervous system. Depressants calm irritability and anxiety and may
induce sleep.
• Alcohol: $40 billion annually US- most widely used and abused drug
• Barbiturates: downers- relax and create a feeling of well being- 25 in
use in medicine- 5: amobarbital, secobarbital, phenobarbital,
pentobarbital and butabarbital used for most: “barbs, yellow jackets,
blue devils and reds”
10-70mg dose. Methaqualone (Quaalude) powerful sedative.
• Tranquilizers: relax “without impairment”- Reserpine and
chlorpromazine reduce anxiety of mental patients- mild tranquilizersdiazepam (Valium), chlordiazepozide (Librium) and meprobamate
(Miltown) produce psychological and physical dependancy
• Glue sniffing and gas propellants: exhilaration and euphoria- liver,
heart and brain damage
Stimulants
• Stimulant- A substance taken to increase alertness or
activity.
• Amphetamines: synthetic drug: uppers or speed: 5-20 mg.
Amphetamine or Methamphetamine. Restlessness,
instability and depression. Inject or smoke- Ice
• Cocaine- Sigmund Freud experiments with drug- the need
for food and sleep was completely banished. Once used for
local pain killer. Powerful stimulant. Most commonly
sniffed through mucus membranes of the nose. Crack
smoked. Crack users rarely kick the habit. Abuse on the
rise. Not harmless. - mental depression, cardiac arrest
Club Drugs
• Club drugs- Synthetic drugs that are used at
nightclubs, bars, and raves. Club drugs include,
but or not limited to, MDMA (ecstasy), GHB
(gamma hydroxybutyrate), Rohypnol (roofies),
Ketamine, and Methamphetamine. MDMA
• GHB-gamma hydoxybutyrate,
• Rohyphnol (roofies)- muscle relaxation and loss of
consciousness- rape drug
• Ketamine
• Methamphetame
Anabolic Steroids
Anabolic steroids- Steroids that promote muscle
growth. Chemically related to male sex hormone,
testosterone.
Widespread attention for enhancing athletic
performance. In 1991, the US government
classified them as controlled dangerous substances
Drug Control Laws
Controlled Substances Act
Legal Drug Classification System to prevent and control drug abuse
5 schedules of classification for controlled dangerous substances on
the basis of a drug’s potential for abuse, potential fo physical and
psychological dependence and medical value
Flexible: as the US attorney general has the authority to add, delete,
or reschedule a drug as more information becomes available
Schedules I and II are subject to manufacturing quota
Criminal penalties for unauthorized manufacture, sale or
possession are related to the schedules. Most severe are for I and
II punishable by up to 20 years and 1 million for individual or up to
5 million for other than individuals
Controlled Substances Act Schedule
Drug Identification
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Selection of an Analytical Scheme.
Factors including amount of substance to be analyzed, time available,
and disposition of the analyzed material.
• The general principles that are followed when developing an
Analytical Scheme are as follows.
1. Visual examinations remain the first method employed.
2. Examinations must move from general to specific.
3. The schemes and processes must adhere to generally accepted
processes and tests accepted in the field.
4. Whenever possible perform at least one specific test.
5. Pay attention to the possibility that the sample may be needed as an
exhibit in court.
6.If there is not enough material for a complete battery of tests those that
do not destroy the sample should be performed first.
7. Use the tests that have the most telling results.
Drug Identification
• Screening test- A test that is nonspecific and
preliminary in nature to reduce the possibilities to
a manageable number- series of color tests.
• Once the number of possibilities has been
substantially reduced, the second phase of analysis
must be devoted to pinpointing and confirming the
drug’s identity
• Confirmation- A single test that specifically
identifies a substance.
Drug Identification tests
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Color tests
Microcrystalline tests
Chromatography- TLC
Spectrophotometry- UV Spec, IR Spec
Mass spectrometry- coupled to GC: GC-MS
Screening Tests
•Provides information about class of drugs involved
Color tests
• Marquis (2 % formaldehyde in sulfuric acid): Purpleheroin, morphine and opium derivatives. Orange brown
for amphetamines and methamphetamines
• Dillie-Koppanyi (1% cobalt acetate in methanol followed
by 5% isopropylamine in methanol)- Violet-blue for
barbituates
• Duquenois-Levine (A= 2% vanillin and 1% acetaldehyde
in EtOH- B= concentrated HCL and C= chloroform)
Purple in C layer for marijuana
• Van Urk (1% p-dimethyaminobenzaldehyde in 10%
concentrate HCl and EtOH). Blue purple- LSD
• Scott Test (A=2% cobalt thiocyanate dissolved in H20, B=
HCl and C=Chloroform) Cocaine – A blue, B pink and C
blue reappears
Microcrystalline Tests
• Microcrystalline tests- Tests to identify
specific substances by the color and
morphology of the crystals formed when the
substance is mixed with specific reagents.
Chemical Microscopy
• Reagents are aqueous solutions
of metallic salts
• Drug materials form complexes
with reagent
• Complexes are crystals
• Observed microscopically
• Closely related materials give
very different crystals, easily
distinguished
Heroin with Mercuric Iodide
Confirmatory Tests
• Chromatography- TLC and GC
• FTIR- Fourier Transform Infrared Spec
• Chemical Microscopy
Thin Layer Chromatography (TLC -1)
• Moving liquid phase, solid
stationary phase
• TLC Procedure
– Sample is dissolved in a solvent
– Spotted onto the lower edge of the
plate
– The plate is placed into a closed
chamber with liquid
– The liquid slowly rises up by
capillary action. Separation occurs as
the components with the greatest
affinity for the moving phase migrate
faster
– Visualized UV fluorescence or
developed with a chemical reagent
spray  color spots
TLC -2
• Questioned sample (Q) must be developed alongside a standard
or known (K) sample. If Q and K travel the same distance up the
plate from the origins then they can be tentatively identified as
the same
• ID cannot be considered definitive as other materials may have
similar migration
• Distance traveled up can be assigned an Rf value = distance
traveled by the component divided by the distance traveled by the
liquid phase. For example if the moving phase travels 10cm and
spot 8cm then Rf = 8cm/10cm = 0.8
• Rapid and sensitive down to 100ug
• Principal application is detection and identification of
components in a complex mixture
– Separate drugs from diluents
– Need to know something about identity from other tests
– Complements color and crystal tests
Q K
Spectrophotometer
• Instrument used to measure and record the absorption spectrum of a
chemical substance
• Components- 1. Radiation source
– 1- Radiation source (UV, vis, IR)
– 2. Monochromator or frequency selector
– 3. Sample holder
– 4. Detection to convert electromagnetic radiation into an electric
signal (digitizer)
– 5. Recorder
• UV spec - useful to establish probable identity of drugs
• FTIR- spedivically identify a substance
UV and Visible
Spectrophotometry
• Measures the absorbance
of UV and visible light as
a function of wavelength
or frequency
• UV spec of heroin has
max absorption at 278nm
providing materials
probable identity
• Will not provide definitive
result - other material may
have a similar UV
absorption
IR Spectrum
• IR specs provide far more
complex patterns
• Different materials
always have distinctively
different IR spectra
• Each IR spectra is
equivalent to a
“fingerprint” of that
substance and no other
• Fourier transform infrared
spectrophotometer FT-IR
• Considered specific in
itself for identification
GC- Mass Spectrometry
Collection and Preservation of
Drug Evidence
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Simple task with minimal precautions
Properly packaged and labeled
Prevent loss and cross contaminations
Volatiles in airtight container
Marked with information to ensure identification
for future legal proceedings and to establish the
chain of custody
• Helps to have background information and any
test results completed in the field
Summary 1
Drug is a natural or synthetic substance that is used to
produce physiological or psychological effects in
humans or other higher order animals
Narcotic- Analgesic or pain-killing substance that
depresses vital body functions such as blood pressure,
pulse rate, and breathing rate. The regular administration
of narcotics will produce physical dependence.
Examples are the opium derivatives and opiates
Hallucinogen- A substance that induces changes in mood,
attitude, thought, or perception. Examples are marijuana,
LSD, PCP and MDMA
Summary 2
• Depressant- a substance used to depress the functions of
the central nervous system. Depressants calm irritability
and anxiety and may induce sleep. Examples are alcohol,
barbituates, tranquilizers and glue sniffing
• Stimulant- A substance taken to increase alertness or
activity. Examples are amphetamines and cocaine
• Club drugs- Synthetic drugs that are used at nightclubs,
bars, and raves. Club drugs include, but or not limited to,
MDMA (ecstasy), GHB (gamma hydroxybutyrate),
Rohypnol (roofies), Ketamine, and Methamphetamine.
MDMA
• Anabolic steroids- Steroids that promote muscle growth.
Chemically related to male sex hormone, testosterone.
Summary 3
• Controlled substances schedules are a legal drug
classification system to prevent and control drug abuse
• There are 5 schedules with I and II being the most
dangerous with accordingly the highest penalties for
manufacture, sale or possession
• Drug chemists conduct screening tests to narrow down the
possibilities and then confirmatory tests to identify the
drug. Typically FTIR or GCMS is used
• Collection of drug evidence should be done to prevent loss,
and contamination. All evidence should be marked and
chain of custody established.