Varian 450-GC, User Manual

Page: 78 / 205

AutoSamplers
Page: 122 User Manual 450-GC Varian, Inc.
SAMPLER CONFIGURATION
The AutoSampler will be delivered in one of two (Liquid or SPME)
configurations.
Default is the Liquid Sampling configuration.
The SPME operation can be thought of as fundamentally reversed from liquid
sampling in terms of the actions t he plunger performs during the sampling
process. In liquid sampling, the plunger is at its home state more or less fully
descended and sampling is done by withdrawing the plunger from the syringe
barrel in order to take an aliquot for injection. In SPME however, the plunger is
at the top of its travel when it is in the home position and the SPME fiber must
be exposed by inserting the plunger into the fiber holder barrel to expose the
fiber.
•
Installation of the SPME mode, on page 142.
•
Installation of the Liquid Sampling mode, on page 149.
The SPME Samplin g mo de can not be selected by the 450-GC
display/keyboard. In order to configure th e system to use SPME you
must set a switch on t he syringe sled to the correct posit ion and install
the special SPME fiber hol der block. This means of setting up the
system to use SPME was adopted to avoid unintentional damage to
either SPME hardware or syringes. Ones the installation is completed,
the 450-GC will recogni ze the sampler mode.