
Catalyst – entrance quiz! Using your notes • Name two club drugs and their effects. • Whats the difference between cocaine and crack cocaine?
Aim • What are the tests that forensic scientists use to determine the identity of drugs • Agenda • Catalyst • Mini Lesson • Practice
Screening and Confirmation • Scenario: A police officer stops a motorist who is driving erratically and notices a bag of white powder on the front seat of the car. S/he has no idea what it is. How can S/he figure it out?
Screening and Confirmation • When faced with a scenario like this, forensic scientists have to develop a plan of action. • Two phases • Screening phase • Confirmation phase
Screening test • The drug could be 1000+ commonly encountered drugs (Rx too) • Screening test – a preliminary test used to reduce the number of possible identities of an unknown substance • Many of these = color tests. • Shows what is possible and what it is not. • DOES NOT CONFIRM IDENTITY
Why can screening tests not confirm identity? • Other drugs/chemicals might react in similar ways
Color Tests • Many drugs turn certain colors when brought into contact with a chemical reagent • Chemical reagent – a substance used to detect other substances • **only for screening purposes!*
Marquis • Reagent purple in presence of heroin, morphine, opiates • Reagent orange/brown in presence of amphetamines and methamphetamine
Dillie-Koppanyi • Reagent violet/blue in presence of barbituates
Duquenois-Levine • Test for marijuana • Add a series of chemical solutions • Turns purple when chloroform is added
Van Urk • Reagent blue/purple in presence of LSD
Scott Test • Two steps! • Reagent blue in presence of cocaine • When add hydrochloric acid clear pink
example • Watch my mini experiment!
Phase Two: Confirmation • Confirmation test - a single test that specifically identifies a substance.
1st – make a table organizing the color indicator tests • 2nd – with a partner, write a scenarios where unknown drugs were found. Then write a 1 paragraph description of what tests you would perform and what results you might see.
Over the Counter Drug Lab February 21st, 2010
Catalyst • What is an over the counter drug? • What are examples of over the counter drugs that people use pretty commonly • What is the difference between a screening test and a confirmation test?
Aim • What are other screening tests performed on over the counter drugs? • How do we perform these tests? • Agenda • Catalyst • Go over lab procedure • Complete lab
Learning Target • I CAN describe AND perform the laboratory tests normally used to perform a routine drug identification analysis
Take 5 minutes to read the lab • Try to fill out the table
Safety precautions • Wear goggles • Do everything over paper towels • If theres a spill, contact me. • If i make someone in your group take a time out, dont complain.
When you are done • Wash out your materials in the sink. • Leave on papertowels to dry. • Return bottles/samples up to front
Lab questions due tomorrow • Try to complete them now • Complete sentences • Individually. • Be neat. Dont fold up your paper .
chromotography February 23rd, 2010
catalyst • What happens when your jeans are too long and you walk around in the snow after a snowstorm and the snow has begun to melt? • What do your jeans look like once youve gone inside? • What do they look like when theyve dried hours later?
Aim • What is chromotography? What is chromotography used for? • Agenda • Catalyst • Demo • Mini lesson • Practice
Demo • Watch my setup.
Chromotography • Way to separate and identify the components of a mixture • Useful for analyzing drug speciments that might be diluted or “cut”
Idea: chemical substances escape into surrounding environment • Example: nail polish • Liquid phase: liquid nailpolish in bottle • Gas phase: gaseous vapors of nailpolish in the air
Separation of mixtures • If you have salt water, how do you separate the salt and water?
Many types of chromotography • Thin layer chromotography • Gas chromotography • Ultraviolet and visible spectophotometry • Infrared spectophotometry • Mass spectophotometry • All are ways to figure out components of mixtures. Used across the board in allllll the sciences.
Thin Layer Chromotography (our focus) • Uses a solid stationary phase and a moving liquid phase to separate pieces of a mixture. • Quick and easy method • Need tiny sample
Show you demo online first, then i’ll explain the details • http://www3.wooster.edu/Chemistry/analytical/gc/default.html
Each piece of mixture is separated by polarity • If molecule is POLAR, will not travel far • If molecule is NONPOLAR, it will travel far.
Procedure • A thin plate covered in a special coating (silica gel) • Sample must be in a dissolved form • One tiny sample placed on lower edge of place, about 1 cm away from bottom • Placed in a little bit of liquid. The liquid moves up the plate takes with it certain dissolved parts.
Most often parts of mixture are clear • So you have to use a different chemical reagent to show the color
Rf value • Each chemical will move up a plate the same distance. • Ex: cocaine always moves up to the same level • Ex: blue ink will always move up to the same level.
Rf value • Distance traveled by component distance traveled by liquid • example:
Rf value • Distance traveled by component distance traveled by liquid • example:
Homework • Your discussion questions in paragraph form • The mini worksheet i gave out now.
Catalyst • What is the equation for Rf value? • What is Rf value useful for? • How far the spot traveled • How far the liquid traveled
Catalyst • Write 3 sentences explaining what we did in the lab. • Im coming around to check if youve done this in 3 minutes.
Aim • How do we conduct TLC analysis • Write mini lab write up
Learning Target • I can describe, explain , and perform the process of chromatography
Rf Value Analysis • How do we do it? • Need ruler & calculator • Distance moved by substance • Distance moved by solvent