Chromatography Flashcards
Use of paper chromatography
to separate mixtures, especially dyes and pigments
How does paper chromatography work
Solvent (mobile phase) is placed on paper (stationary phase)and is drawn up by capillary action.
-different substances will be soluble to water and attracting to the paper =absorb onto surface and desorb into a solvent at different rates due to their nature
How does thin layer chromatography work
Solvent (mobile phase) is placed on layer of silica gel (stationary phase)
some particles stick better to gel= lag depending on solubility and charge and their interaction with matrix
What is retardation factor
ratio between distance travelled by sample and distance travelled by solvent
How does gas chromatography work
Inert gas (mobile phase) injected into long thing tube of silica gel/alumina
What is Rt
retention time
time taken for results in a value
How does high performance liquid chromatography work
Liquid (mobile phase) solid silica material (stationary phase)
What is HPLC used for
Large organic molecules + thermally unstable
What does desorb mean?
Action of substance moving from stationary to mobile phase
What does absorb mean
Action of substance attracting to surface of a material
What is mobile phase
Phase carrying solutes/dissolves mixture
What is stationary phase
fixedin place during chromatography where solutes absorb
What is analyte?
substance separates from process
What is an element?
substances composed of only one type of atom
What is a compound?
composed of more than 1 type of atom strongly bonded together
