Changing Or Cleaning Liners; Suggestions For Packed Inlets With 530-Μm Columns; Adapting For Cool On-Column Injection - Agilent Technologies 7673 Operating Manual

Changing or cleaning liners

Most samples contain nonvolatile material that accumulates on and partially
pyrolyzes on the liner. Replace the liner or clean the liner periodically.
Some active components interact with the glass liner and glass wool plug of the
capillary liner. If these components are in the sample, the liner should be
deactivated before installation and periodically replaced or cleaned and
deactivated. There are several commercially available solutions for
deactivating the liner. Take the appropriate safety precautions when using any
of these solutions. Refer to the Agilent analytical consumables and supplies
catalog for deactivated liners.
Suggestions for packed inlets with 530-µm columns
When using a heated, packed inlet with a 530-µm column, do the following:
• Install the column so that no more than 1 to 2 mm of the column extends
past the ferrule. This avoids large unswept volumes at the base of the inlet.
• Use polyimide ferrules (Vespel) instead of graphite. A small portion of the
column ferrule is exposed to sample vapor.
• Insulate the part of the inlet that projects into the oven. If the oven is
programmed to increase temperature, the lower part of the inlet could
become a cold spot.

Adapting for cool on-column injection

For cool on-column inlets, you must specify on-column injection with the
sampler parameters so that the injector:
• Slows the carriage speed to 500 milliseconds. The syringe needle moves
more slowly into and out of the inlet and spends more time in the inlet.
• Lowers the tip of the syringe needle an additional 19 mm (3/4-inch) to the
column.
You can use the slow injection parameter along with on-column injection. This
adds the following change to the injection:
Preparing for Operation
Adapting for cool on-column injection
55