L6: Chromatography

Question 1

Normal Phase Chromatography

Answer 1

stationary phase is more polar than mobile phase

Question 2

Reversed Phase Chromatography

Answer 2

Mobile phase more polar than stationary phase

Question 3

Ion Exchange Chromatography

Answer 3

stationary solid phase selectively binds anion/cation onto it due to electrostatic attraction and effect separation

Question 4

Molecular Exclusion/ Gel Permeation Chromatography

Answer 4

attractive interaction between stationary phase and analyte; liquid/gaseous phase passes through porous gel and separates molecules according to size (small pores in gel blocks large solute molecules but allow smaller molecules to enter and flow through a large volume)

Question 5

Affinity Chromatography

Answer 5

one kind of molecule becomes attached to molecule that is covalently bound to stationary phase while the other molecules wash through

Question 6

Total retention time (tr)

Answer 6

time needed by analyte component to migrate from column inlet to column end (injector to detector)

Question 7

Dead time (t0)

Answer 7

time required by an inert compound to migrate from inlet injector to column inlet

Question 8

Net Retention time (tr’)

Answer 8

time that analyte component remains in stationary phase