PART 3
Forensic Drug Analysis
CONFIRMATION TESTS
LABORATORY BASED DRUG TESTS
Confirmation Tests
Tests that are performed after screening
tests are complete to signify exactly what
the unknown substance is.
Qualitative and Quantitative Tests are performed.
A Qualitative test is performed first (to tell
what type of drug is present)
A Quantitative test is done second (to tell how
much drug is present.) Example: A white
powder maybe 20% cocaine, 80% baking soda
FIVE tests used by Forensic
Chemists to determine an
unknown drug
1.
2.
3.
4.
5.
COLOR TEST (5) PRESUMPTIVE TEST
MICORCRYSTALLINE TEST CONFIRMATION TEST
CHROMATOGRAPY TEST (2) CONFIRMATION TEST
SPECTROPHOTOMETRY (2) CONFIRMATION TEST
MASS SPECTROMETRY CONFIRMATION TEST
COLOR TEST (5)
1. Marquis Test= Identifies alkaloid drugs (pH 8.2-11.0). A mixture of
formaldehyde and sulfuric acid drips into the drug for a color change. The
color indicates the drug. MOST ECSTACY DRUG KITS have the contents of
the Marquis Test.
Dark purple= Ecstacy, Orange-brown= Meth, Excederin= dark red
2. Dillie-Koppanyi Test=
reagent= methanol
Barbiturates turn violet-blue
3. Duquenois-Levine Test= in the test is Ethanal, Vanillin, HCl,
chloroform. Marijuana turns purple
4. Van Urk Test=an aldehyde in HCl/ H2SO4
LSD= purple,
Psilocybin (mushrooms)= red-brown
5. Scott Test= reagent= Cobalt thiocyanate/HCl/Chloroform
Cocaine turns blue, pink, blue
Spot tests Identification
Reagent
Positive Result
Possible Drugs Present
Marquis
Purple
Orange-Brown
Heroin, Morphine, & most
opium derivatives
Mixture of Amphetamines
and Methamphetamines
Dillie-Koppanyi
Violet-Blue
Barbiturates
Duquenois-Levine
Purple
Marijuana
Van Urk
Blue-Purple
LSD
Scott Test
Blue
Cocaine
Marquis
Dillie-Koppanyi
Duquenois-Levine
MICROCYSTALLINE TEST
MICROCYSTALLINE TEST
A test in which the scientist adds a drop of the
suspected substance to a chemical on a slide.
The mixture will begin to form crystals. Each
type of drug has an individual crystal pattern
when seen under a polarized light microscope.
COCAINE
METHAMPHETAMINE
CHROMATOGRAPHY
Forensic Chromatography Lab
LC or GC
High performance liquid chromatography and
gas chromatography are extremely sensitive
techniques utilized in the analysis of drugs, body
fluids, fire accelerants.
Types of Chromatography
•
•
•
•
•
•
Paper Chromatography
Gas Chromatography
Liquid Chromatography
Thin-Layer Chromatography
Ion Exchange Chromatography
Affinity Chromatography
Chromatography is used extensively in forensics, from
analyzing body fluids for the presence of illicit drugs, to fiber
analysis, blood analysis from a crime scene, and at airports to
detect residue from explosives
CHROMATOGRAPY
1. Separate and Identify components
of a drug.
2. It involves passing a mixture
dissolved in a "mobile phase"
through a stationary phase, which
separates the compound to be
measured from other molecules in
the mixture based on differential
partitioning between the mobile
and stationary bases
Chromatograph of THC
Thin-Layer Chromatography
• Thin layer chromatography (TLC) is a
chromatography technique used to
separate mixtures.
• Thin layer chromatography is performed
on a sheet of glass, plastic, or aluminum
foil, which is coated with a thin layer of
adsorbent material, usually silica gel.
• This layer of adsorbent is known as the
stationary phase
Gas Chromatography
• Book on chromatography
• $100
• 300 pages of graphs
GC machine
• GC machines can cost $600- $30,000
• Average cost is $16,000
GC analysis
Spectrophotometry
Mass Spectrometry
• A band of charged particles of different
masses formed when a beam of ions is
passed through the deflecting fields of a
mass spectroscope, from which the
masses of atoms, molecules, or isotopes
can be determined.
Mass Spectrum of Ephedrine and
Pseudoephedrine
UV-visible light spectrometers
UV-visible light spectrometers are employed
for accurate quantitative analysis of colored
samples
Infrared (IR) Spectrophotometry
• Equivalent to a human’s fingerprint in
terms of drug identification
IR spectrum of Cocaine base
How much does a Mass-Spec
cost?
$100,000 to $800,000 depending on functions
Mass Spec of Caffeine
GC/MS
Gas chromatography/mass spectrometry
• Isolates the drug from any mixing agents or other
substances that might be combined with it.
• A small amount of the substance is injected into the gas
chromatograph.
• Different molecules move through the chromatograph's
column at different speeds based on their density.
• For example, heavier compounds move more slowly,
while lighter compounds move more quickly.
• Then the sample is funneled into a mass spectrometer,
where an electron beam hits it and causes it to break
apart.
• How the substance breaks apart can help the
technicians tell what type of substance it is.
GC/MS
Gas Chromatograph Mass Spectrometer, is used to
separate, detect, identify and determine the content of
chemicals in a large variety of samples.
GC/MS is the preferred confirmatory method of
analysis by the National Institute on Drug Abuse