Question

If one choose to work on a column packed with smaller particle sizes, what might be the biggest disadvantage of using smaller particles (in size) as packing material (stationary phase) in column chromotography for separation of mixtures?

Answer 1

The main disadvantages of using Smaller particle size for Column packing in column chromatography for seperation of mixtures is:

1) Main drawback is back Pressure. The operating pressure and particle size have inverse square relationship. A decrease in particle size by factor of 2 would yield a pressure increase by factor of 4. Whenever pressure is applied from top of column during column run, removal of it becomes little tricky, as the small particle size packing may distort and create gaps in-between to the otherwise neat packed column.

2) Another disadvantage is Column Clogging. Smaller particle size means space between the particle or interstitial space is smaller. The interstitial space is where large impurities can become stuck and cause column clogging. Every column has a frit on front of the column as a last resort filter to keep impurities out. Liquid may not flow smoothly for compound seperation and seperation may not be as desired.