The wide-bore column offers, compared to other capillary columns, a much lower number of plates due to their large internal diameter and a thick stationary phase film. However, compared to packed columns,  wide-bore columns offer many advantages:

• Efficiency 
  This is evident from the H-u curve for both columns. For the wide-bore column, the H-u curve is situated below that of a packed column at all carrier gas velocities. Peak broadening for wide-bore columns is 1.5 to 3.0 times less compared to packed columns. Comparing the situation whereby both column types have a certain gas velocity and the analysis time is the same for both systems, the wide-bore has an increase in plates of approximately 1.5.

Packed vs wide-bore efficiency

• Analysis time
  The wide-bore column is the slowest capillary column, but faster than the packed column. One of the main advantages in changing from a packed column to a wide-bore column is that a faster analysis speed is almost always obtained. The reason for this is that the particles in packed columns are rather large which means that diffusion distances are large and equilibration is slow.

Because of the 'wide-bore' and consequently the high permeability, wide-bore columns can be used under a wide range of gas flows. Under 'packed' conditions, wide-bore columns are used at flow rates far above the optimum value(> 10 mL/min), resulting in fast analysis times at relative low column efficiencies.

• Sample Capacity
  The sample capacity of the wide-bore column apparently differs widely from the capacity of 'normal' capillary columns. Since the sample capacity depends on the amount of stationary phase, the percentage of stationary phase in the packed columns should be compared to the film thickness in capillary columns with respect to sample capacity. In general the capacity of a low-loaded packed column matches a thin film wide-bore. A high-loaded packed column can be compared to a thick film wide-bore column. Therefore comparable injectors may be used in both cases. In practice a wide-bore column can be used with a direct injector, which is normally used in conjunction with packed columns.

If the amount of stationary phase decreases i.e. when changing from a packed to a capillary column, the retention times also decrease and dilution of the sample is restricted. The overall effect is that the analytes elute at similar concentrations in the carrier gas and sensitivity is not affected. The actual peak size will also depend on the type of detector and the operating conditions.

Sample capacity of packed column

Sample capacity of wide-bore column