Problems and exercisesChromatographic Methods
1. Classify
State whether each technique is planar or column chromatography and what its mobile phase is: a) thin-layer chromatography; b) gas chromatography; c) HPLC; d) paper chromatography.
2. Thin layer on silica gel
On a silica gel plate, a compound moves 3.0 cm while the solvent front moves 7.5 cm. Calculate its Rf. If an alcohol and a hydrocarbon are eluted on the same plate, which one moves further?
3. The big ones come out first
Why do large molecules come out before small ones in size-exclusion chromatography?