UsingFerruleswithSRI GCs
Graphite reducing ferrules are
availablewith two holes instead of
one. Here a two hole hard graph-
ite reducing ferrule secures
two .53mm capillary columns into
the heated injector. When sample
is injected, it is split onto the two
column.
Here a hard graphite reducing fer-
rule secures the column to theFID
detector. Hardgraphite is pre-
ferred for the column to detector
connection becausehardgraphite
bleeds less producing a flatter
baseline at high temperatures.
Soft ( not hard ) graphite ferrules
can also be used to connect 1/8”
and 1/16” Teflon tubing to fittings.
In the example to the right, a 1/8”
to1/16” graphite reducing ferrule
connects 1/16” Teflon tubingusing
a1/8” nut. Unlike brass or
stainless steel ferrules, graphite
ferrules are less likely to restrict
the flow of gases by crushing the
Teflon tubing.
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