Drugs: Analysis Dr. Jason Linville University of Alabama at Birmingham

Summary Analysis of Chemical Drugs Instrumental Examination Botanical Examination

Chemical Examination White Powder or Pills What are they?

Chemical Examination 3 steps in processing unknown chemicals: Screening step Sample preparation step Confirmatory test

Chemical Examination Screening Test: Color Test Small amount of chemical in spot plate Drop of color changing reagent added Color change noted

Chemical Examination Screening Test: Color Test Several tests done at same time. Adulterants or diluents may affect color

Chemical Examination Screening Test: Microcrystal Test Small amount of sample dissolved in solution. Test reagent added; contains another chemical that reacts with drug. Insoluble crystal formed.

Chemical Examination Screening Test: Microcrystal Test Shape of crystal suggests type of drug. Impurities may cause unusual crystal formation.

Chemical Examination Screening Test: 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

Chemical Examination Screening Test: Thin Layer Chromatography (TLC) Different solvents result in different distances Some systems include color change components

Chemical Examination Screening with Instrumentation: 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

Chemical Examination Screening with Instrumentation: UV Spectroscopy Different drugs create a different pattern

Chemical Examination Screening with Instrumentation: Gas Chromatography Similar to TLC; different chemicals will move at different rates through a capillary.

Chemical Examination Screening with Instrumentation: 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.

Botanical Examination Marijuana Macroscopic Exam: Leaf and stem structure Microscopic Exam: Tiny hairs on leaf surface

Botanical Examination Marijuana (Resin ID) Color test: Tests for chemical THC TLC: Tests for chemical THC

Botanical Examination Peyote Macroscopic Exam: Look for cotton-like tufts Test for alkaloids: TLC and Gas chromatography Confirming mescaline not necessary

Botanical Examination Mushrooms Macroscopic Exam: Can identify mushrooms that might contain psilocybin Screen for psilocybin: Color test, TLC, and UV spectroscopy Confirmed with MS and IR spec (later slides)

Chemical Examination 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.

Chemical Examination 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

Chemical Examination 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

Chemical Examination 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

Confirmation Techniques Confirmation identifies the specific type of drug. Heroin

Confirmation Techniques Confirmation identifies the specific type of drug. ?

Confirmation Techniques 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.

Confirmation Techniques Confirmation (Mass Spectroscopy)

Confirmation Techniques 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.

Confirmation Techniques Confirmation (Infrared Spectroscopy) Different drugs = different patterns Pattern is specific to one drug