- Hewlett-Packard Reference Manual

156
Preventive Maintenance
This chapter includesmaintenance, cleaning, and leak•testingHP 5890
SERIES II (hereafter referred to as HP 5890) inlet and detector systems.
Conditioning columns
Columns may contain contaminants; conditioning drives off unwanted
volatiles, making the column fit for analytical use.
New packed columns should be conditioned since they often contain
volatile contaminants absorbed from the air. It may also be necessary to
condition a used column that has been stored for some time without end
caps or plugs to exclude air.
Conditioning is not a serious problem with capillary columns since there
is little stationary phase. For the same reason, however, conditioning
must be gentle not to drive stationary phase from the column.
The following are general guidelines for conditioning:
1. Switch off detectors! Shut off support gases, if any, to detectors
(particularly H
!).
2. a. If the column to be conditioned is already installed, disconnect its
detector end.
b. If the column to be conditioned is not already installed, connect
one end to an available inlet. Do not connect the remaining end to
a detector!
For a split/splitless(or split•only)capillary inlet, if a capillary
column is to be conditioned, install the proper insert and attach
the column in the normal manner, making certain about 7.5 mm of
column extends above (in front of) the column nut (
25 mm from