drugs: analysis
DESCRIPTION
Drugs: Analysis. Summary. Analysis of Chemical Drugs Instrumental Examination Botanical Examination. Chemical Examination. White Powder or Pills. What are they?. Drugs > Chemical Exam. 3 steps in processing unknown chemicals:. Screening step. Sample preparation step. Confirmatory test. - PowerPoint PPT PresentationTRANSCRIPT
Drugs: Analysis
Summary
Analysis of Chemical Drugs Instrumental Examination Botanical Examination
Chemical Examination
White Powder or Pills
What are they?
3 steps in processing unknown chemicals:
Screening step
Sample preparation step
Confirmatory test
Drugs > Chemical Exam
Color Test
Small amount of chemical in spot plate
Drop of color changing reagent added
Color change noted
Drugs > Chemical Exam > Screening
Color Test
Several tests done at same time.
Adulterants or diluents may affect color
Drugs > Chemical Exam > Screening
Microcrystal Test
Small amount of sample dissolved in solution.
Test reagent added; contains another chemical that reacts with drug.
Insoluble crystal formed.
Drugs > Chemical Exam > Screening
Microcrystal Test
Shape of crystal suggests type of drug.
Impurities may cause unusual crystal formation.
Drugs > Chemical Exam > Screening
Thin Layer Chromatography (TLC)
Dot of drug placed at bottom of paper or thin silica plate
Bottom dipped in solvent; solvent diffuses up plate
Solvent carries drug up paper; distance depends on drug
Drugs > Chemical Exam > Screening
Different solvents result in different distances
Some systems include color change components
Thin Layer Chromatography (TLC)
Drugs > Chemical Exam > Screening
UV Spectroscopy
Sample dissolved in liquid; placed in cuvette.
A range of UV light wavelengths are passed through solution.
Some light will pass through; some light will be absorbed
Drugs > Chemical Exam > Screening
UV Spectroscopy
Different drugs create a different pattern
Drugs > Chemical Exam > Screening
Gas Chromatography
Similar to TLC; different chemicals will move at different rates through a capillary.
Drugs > Chemical Exam > Screening
Gas Chromatography
The time it takes to pass through the capillary gives an indication of which drug it is.
Drugs > Chemical Exam > Screening
Botanical Examination
With botanical evidence, additional steps can be added to the screening process.
Marijuana
Macroscopic Exam: Leaf and stem structure
Microscopic Exam: Tiny hairs on leaf surface
Drugs > Botanical Exam
Marijuana (Resin ID)
Color test:Tests for chemical THC
TLC:Tests for chemical THC
Drugs > Botanical Exam
Peyote
Macroscopic Exam:Look for cotton-like tufts
Test for alkaloids:TLC & Gas chromatography
Confirming mescaline not necessary
Drugs > Botanical Exam
Mushrooms
Macroscopic Exam:Can identify mushrooms that contain psilocybin
Screen for psilocybin:
Color test, TLC, and UV spectroscopy
Confirmed with MS and IR spec (later slides)
Drugs > Botanical Exam
Screening Summary
All screening tests give an indication of what the drug is.
Since some drugs behave alike during screening tests, confirmation of the drug type is needed.
Drugs
Sample Preparation
In many cases, the identity of the drug must be confirmed for prosecution.
Before identification, it must be separated from other chemicals in the mixture
Drugs
Sample Preparation (Separation)
1. Physical Separation: particles are separated based on microscopic appearance.
2. Dry Wash or Dry Extraction
Dry Wash: Liquid dissolves adulterants; solid drug left behind
Dry Extraction: Liquid dissolves drug; solid adulterants left behind
Drugs > Sample Preparation
Sample Preparation (Separation)
3. Liquid/Liquid Extraction: Entire sample dissolved in aqueous (water)
liquid Organic liquid (oil-like) mixed with solution Organic liquid removes adulterants Sample remains in aqueous layer
Drugs > Sample Preparation
Confirmation Techniques
Confirmation identifies the specific type of drug.
Heroin?
Mass Spectroscopy
MS will smash a molecule into pieces and measure the mass of the pieces.
Every drug will break in a unique way, creating a unique amount of pieces.
Drugs > Confirmation
Mass Spectroscopy
Drugs > Confirmation
Infrared Spectroscopy
Similar to UV spectroscopy, except a range of infrared light wavelengths are passed through a sample.
Some light passes through; some light is absorbed.
Drugs > Confirmation
Infrared Spectroscopy
Different drugs = different patterns Pattern is specific to one drug
Drugs > Confirmation