How chromatography works?

The lab class demonstrated how proteins could be isolated using hydrophobic interaction chromatography. The report is in two sections, to describe the purification technique and to evaluate its effectiveness. How chromatography works? Part 1) words. (75%) With the use of diagrams describe in full how the Hydrophobic Interaction Chromatography works and can be used to purify proteins from a bacterial extract. How chromatography works? Part 2) 250 words. (25%) For the purification of the GFP protein, outline the limitations of the technique and how you can assess the purity of the protein. Can you suggest any other techniques that could further purify the GFP protein.