D9 drug detection and analysis Flashcards
what are steroids
lipids w 4 fused rings in structure – steriodal backbone
2 examples of steriods
T-
C-
testosterone
cholesterol
what is testosterone
male steroid hormones, performance enhancing drugs
most common method for detection of steorids in blood? (for drug tests)
gas chromatography
mass spectrometry
what does mass spec do vs gas chromatography
mass spec: identifies and quantifies the components
gas chromatography: seperates chemical mixture into pure chemicals
3 steps for mass spectromatry
- mass spectrometer vaporises the sample, generating positive ions from components
- ions are accelerated an deflected in a magnetic field, seperated
- molecules fragment intor structures identifiable by charge to mass ratio
what does gas chromatography do
seperates the chemical MIXTURE into PURE chemicals
what property of the mixture (urine) allows for gas chromatograpy
the components have different affinities for the stationary and mobile phase
stationary vs mobile phase
stationary: microscopic layer of non-volatile liquid (usually polymer), coated on the walls of an inert solid support
mobile: inert carrier gas eg helium
describe how gas chromatograpy works
1 components of mixture seperated – determined by diff rates at which they move thru the chromatography apparatus
2 rates differ bc boiling points and solubilities – determine relative associations with stationary and mobile phases (liquid and gas)
what factors for the components matter for gas chromatograpy that determines whether theyre stationary or mobile phase
boiling point and solubility
molecules w more time in gas phase = move quicker
incr bp + incr sol = liquid = slower
why is the temperature in the column controlled in gas chromatography
so some components condense and dissolve in the liquid (stationary) phase on the column walls
- changing temp controls retention times = changes amt of seperation
what is retention time in terms of gas chromatography
the specific interval of time in which each component of the mixture is eluted
name the 3 methods for organic structure analysis and identification
mass spectroscopy
infrared spectroscopy
proton NMR
what is ethanol is breath
ethanol established equilibium in the lungs between the solution in the blood anf the gas released in exhaled breath
C2H5OH (aq) <=> C2H5OH (g)
what instruments are used to measure ethanol conc in breath
breathalysers
alcosensor