Dr. KnowIt is still something that has to be done in cases where an old (official) method with a packed GC column needs to be transferred to a more modern capillary column.
In packed GC we have wide internal diameters, a support material carrying the liquid phase and a percentage of phase load (ratio support material vs. amount of liquid phase). In capillary GC we have smaller internal diameters, long columns and a film thickness for the liquid phase.
Conversion of Packed GC Phase Load to Capillary Film Thickness
If the GC is one with flow regulators for packed columns and therefore not suited for the used of small internal ID capillary columns, then you can still use 0.53 mm ID columns under the same conditions. With pressure regulators (electronic pressure control, EPC or their pneumatic equivalent) all types of capillary columns can be used.
Conversion of Packed Column Lengths to Megabore (0.53 mm ID) Capillary (Packed Mode)
Be aware that you will always have less phase in a capillary column and therefore need to inject less, either by injecting less sample volume and/or have a higher split flow.
An indication for the necessary split flow is the following chart (±10-20 %):
