The effects of inner surface roughness of microbore column blanks on column performance

The efficiencies of microbore-2 columns, which are prepared from blanks tha t have a wide variety of inner surface roughness, drop sharply when the siz e of individual surface roughness features approaches the particle size of the packing material. These results suggest that two categories of packed c olumn structure relate to the surface features and yield high (75,000 plate s/m) and low (20,000 plates/m) efficiency columns with 5-mu m particles. Th is installment of "Column Watch" discusses this conclusion in terms of the stability of an agglomerated layer of packing particles on the blank wall w hen subjected to shear forces during column packing.