156Preventive MaintenanceThis chapter includes maintenance, cleaning, and leak•testingHP 5890SERIES II (hereafter referred to as HP 5890) inlet and detector systems.Conditioning columnsColumns may contain contaminants; conditioning drives off unwantedvolatiles, making the column fit for analytical use.New packed columns should be conditioned since they often containvolatile contaminants absorbed from the air. It may also be necessary tocondition a used column that has been stored for some time without endcaps or plugs to exclude air.Conditioning is not a serious problem with capillary columns since thereis little stationary phase. For the same reason, however, conditioningmust 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 H1!).2. a. If the column to be conditioned is already installed, disconnect itsdetector end.b. If the column to be conditioned is not already installed, connectone end to an available inlet. Do not connect the remaining end toa detector!For a split/splitless (or split•only)capillary inlet, if a capillarycolumn is to be conditioned, install the proper insert and attachthe column in the normal manner, making certain about 7.5 mm ofcolumn extends above (in front of) the column nut (25 mm from
