What would be the effect on the results of a column chromatography if......?

Question

what would be the effect on the results of a column (glass tubing) chromatography if:

A) an excessive amount of solvents were used in adding a sample to the column.

B) solvent is not maintained above the absorbent, and a crack develops in the column

Answer 1

A) The sample would be diluted and the components would be spread out in a larger volume when they come off the column, meaning you will have to collect a larger volume when your component of interest comes off the column.  Also, it may be harder to detect since the component of interest will be diluted.  Also, you will likely have to work harder to concentrate your component of interest after you collect the fractions off of the column.  Also, the various components will likely overlap when coming off the column, resulting in more difficulty in finding your specific component of interest.

B) If you let the column run dry, then the components will not separate as you would expect if the column were run correctly.  Also, the samples may actually remix if the cracks are large enough and the results will be useless, since the samples won't separate based solely on the properties of the column matrix.