Varian 4000 GCMS, Installation Procedures Manual

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1.3 GCMS Plumbing and Purging
Use 1/8” brass tubing to plumb 99.995% helium to the back of the GCMS
system. Install the Gas Clean Filter assembly. For an external mode 4000 MS,
Tee the helium output line after the Gas Clean Filter assembly so helium can be
delivered to the GC and the MS. The 4000 MS (in External Mode only) uses
helium Damping Gas that will need to be plumbed into the MS. This MS Damping
Gas is typically installed by teeing off the helium line to the GC and MS after the
Gas Clean Filter assembly. Verify that the helium line pressure is set to 80 psi. at
the cylinder regulator. Ensure the cylinder contains at least 500 psi. of helium.
Before connection to the GC/MS, purge the helium line from the cylinder for 10
minutes at maximum flow. Connect one end of the Tee to the inlet on the back of
the GC, the other to the inlet on the back of the MS. The GC pneumatics need to
purge for at least 1/2 hour to remove any water or air that may have entered
during shutdown.
NOTE: The MS pneumatics (
in External Mode
) will also need to be purged as
described in Section 2 of this document
The column shipped with the system must be installed to achieve the best results
for acquisitions associated with the installation. If an 1177 injector is installed on
the GC, use the 1177 to pass the sensitivity specifications. Condition the injector
and column one time before installing into the MS to prevent column bleed from
contaminating the MS. Condition the injector at 230 °C with a high split ratio
(e.g., 50:1). Condition the column starting at 50 °C, ramping at 5 degrees/minute
up to 300 °C, and hold for 60 minutes unless this exceeds the maximum
allowable operating temperature for the column phase.
1.4 Column Installation Into the MS
Column installation into the 4000 MS transfer line depends on the ionization
mode of the MS and is described in the 4000 Hardware Operation Manual. Note
the ionization mode in which the instrument was shipped and install the column
accordingly.
NOTE: Be sure to leave a significant service loop of column detached from the
column cage so the GC and MS can be easily separated.
At this point the GC and MS can be pushed together on the bench. Ensure that
the transfer line column nut is visible inside the GC oven and the transfer line
rubber boot is inside the hole on the GC side panel.