A2- Chromatography Flashcards
What is chromatography?
chemical separation technique that allows separation of mixtures
What is the basic principle of all chromatography?
components of a mixture dissolved in a fluid will flow through another material/stationary phase
What does separation depend on?
- interaction with stationary phase
- solubility in mobile phase
What is the stationary and mobile phase for TLC?
Stationary: Silica coated plastic plate
Mobile: liquid solvent
What is the stationary and mobile phase for gas chromatography?
Stationary: microscopic liquid film on solid support
Mobile: INERT carrier gas
What is the stationary and mobile phase for column chromatography?
Stationary: solid silica
Mobile: liquid solvent
What do the solute molecules do?
adsorb to the stationary phase
What does the distance travelled depend on?
the interactions between the component in the mobile phase and the stationary phase
What can be used to locate spots?
- UV
- Ninhydrin
- iodine vapour
Why might 2 dimensional TLC be used?
as some amino acids have similar Rf values in different solvents
How would increased solubility due to a more polar solvent impact Rf value?
increase Rf value
as component is more soluble in mobile phase, so travels further up the stationary phase
