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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.
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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
Drugs > Chemical Exam > Screening 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 Thin Layer Chromatography (TLC) • Different solvents result in different distances • Some systems include color change components
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.
Botanical Examination With botanical evidence, additional steps can be added to the screening process.
Drugs > Botanical Exam 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 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 Sample Preparation (Separation) Physical Separation: particles are separated based on microscopic appearance. 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) • 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
Confirmation Techniques Heroin? Confirmation identifies the specific type of drug.
Drugs > Confirmation 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