12. Chromatography Flashcards
Paper chromatography vs TLC
paper = stationary phase, solvent = mobile phase vs slide with silica gel coat = stationary phase, solvent = mobile phase
What is eluent?
The solvent you’re putting the stationary phase in
Is paper or solvent polar or nonpolar?
paper = polar, solvent = nonpolar
How to calculate retardation factor (Rf)?
X/Y; X = distance dot moved, Y = distance of solvent moved
What is reverse-phase chromatography?
when polarity and nonpolarity of phases are switched —> polar molec move up while non polar molec stay
What is column chromatography compared to TLC? What about high performance liquid chromatography?
same thing but solvent moves down b/c gravity. same as column chromatography but more sensitive
Size exclusion vs ion exchange chromatography
beads with holes: small cmpds move thru faster, big cmpds move around slower vs beads with charge: same charge move faster, opposite charge move slower
Affinity chromatography
like column chromatography but tests for binding affinity; beads with a protein receptor
Gas chromatography
stationary phase = liquid, mobile phase = gas; you heat it up –> volatile cmpds (low boiling pt) move faster, high boiling pt move slower
Why do vacuum distillation vs simple vs fractional?
boil stuff over bpt > 150 C vs boil stuff 25-150 C vs < boil stuff with bpt w/in 25 C to e/o, can basically distill any mixture. In order to boil, vapor pressure = atm pressure
Fractional refluxes sample back down over large surface area —> purer
If you wanna know which sln separates first, you find the lowest bpt –> faster distillation rate
Flow cytometry
single cells from cell cultures or tissue samples = stained by protein markers using specific ab
in extraction, how do you know the position of layers?
based on their densities: denser at bottom
