In order to properly configure the system, several parameters must be considered. The most obvious is, of course, the choice of analytical column. The most resolution is obtained with narrow bore capillary columns, but stricter attention must be paid in the transfer of the sample to the column. On the other end of the spectrum, packed columns afford the use of larger samples (even preparative scale for recovery of bulk purified components), but at a sacrifice of chromatographic resolution. Between narrow bore capillary and packed columns lie wide bore capillary columns (also called megabore), and many laboratories find these to be a very useful compromise.
The choice of column influences the type of inlet and detector technology that can/should be employed and should therefore generally be the first consideration in instrument specification. For example, certain detectors function most efficiently with total flows in the 30 mL/min range, whereas narrow bore capillary columns are typically operated in the 1-2 mL/min regime. This does not preclude the use of such detectors with narrow bore capillary columns; the additional gas is added in the form of make-up gas directly into the detector. In a similar fashion, packed columns can be directly interfaced on the inlet end, while capillary and wide bore columns often require a bit more sophistication.