24-01-2013, 04:49 PM
PLOT Columns Instruction Sheet
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Installation Instructions
1. Before removing the previously installed column from the gas
chromatograph (GC), be sure to turn off the detector and cool all
heated temperature zones.
2. Once all zones of the GC are cooled, turn off all gases. Remove
the installed column, plug each end with silicone septa (or
column end caps), and return the column to its original box.
3. Remove the new PLOT column from its box. Remove the septa
(or column end caps) that are on each end of the PLOT column.
Important: If your column is tied onto the metal cage with
high-temperature string, do not remove the string.
4. Attach the appropriate GC capillary nut (fitting) onto the inlet
side of the column. Attach the appropriate GC column ferrule
onto the inlet side of the column.
Fused silica columns:
0.25 mm and 0.32 mm columns, use 0.5 mm ID ferrule
0.53 mm columns, use 0.8 mm ID ferrule
Note: Do not install the capillary column nut (fitting) or ferrule
onto the outlet side of the column at this time; this will be
performed later.
Note: See Helpful Hints section for information on using particle
traps.
5. Trim 2 cm from both ends of the column, making sure that a
clean, square cut is obtained. Install the inlet side of the column
into the GC injection port at the appropriate distance (see your
GC manual to determine the correct installation distance).
PLOT Columns
Instruction Sheet
Table I Approximate head pressures (at 40 °C) using
hydrogen and helium.
B. Column Regeneration
• Occasionally, alumina PLOT columns need to be regenerated to remove
moisture. To regenerate, set the carrier gas head pressure as shown in
Table I, set the GC oven temperature to 200 °C, and condition the column
for 4 hours.
• Occasionally, molecular sieve PLOT columns also need to be regenerated to
remove moisture. To regenerate, set the carrier gas head pressure as shown in
Table I, set the GC oven temperature to 300 °C, and condition the column
for 3 hours.
C. Protection from Particles
• If the PLOT column will be connected to a mass spectrometer (MS), the
pressure drop (vacuum) may dislodge particles into the MS. To prevent
particles from entering the MS, couple the detector end of the PLOT
column to a restrictor (e.g. 5 m x 0.25 mm ID fused silica tubing coated
with 0.25-0.50 μm of a nonpolar stationary phase, such as Rtx®-1 phase).
Use a connector suitable for MS application.
• If the PLOT column will be connected to a non-MS detector, connecting a
particle trap to the detector end of the column is recommended. For fused
silica columns, particle trap catalog numbers are 19753 (for 0.32 mm ID
columns) and 19754 (for 0.53 mm ID columns). For MXT® columns, a fused
silica particle trap can be used with specific MXT® connectors (cat.# 21385
for 0.32 mm ID columns, cat.# 21384 for 0.53 mm ID columns).
• To ensure protection against particles flushing back into a valve/flow switching
setup, connecting a particle trap to the injector end of the PLOT column
is recommended. (See previous bullet for particle trap list.)
D. To prevent high boiling point compounds from contaminating a PLOT column,
use of a precolumn (backflush column) or a valve/flow switching system should
be considered.
E. If the PLOT column is connected using a valve/flow switching setup, it is
recommended to condition the column as instructed under steps 6-11 (previous