Sulfur Trapping at lowPPB levels using theSRI
8610CGasChromatograph
The event table hasRelayA ( the
vacuum pump ) turned on from .1
minutes to 2minutes so the vac-
uum pump sucks the sample in the
Tedlar bag through the trap for 1.9
minutes at the beginning of the
analysis. The trap is at room tem-
perature ( 25C ).
The actual flow depends on the
strength of the vacuum pump and
on the restrictiveness of the trap.
The flow is reproducible from run
to run however.
Typically the flow ratewill be about
300ml/minute, soalmost 600ml of
sample from the bagwill be
sucked through the trap in 1.9min-
utes.
At 2.10minutes the trap starts to
heat up ( Relay F on ). At 4.00
minutes theValco valve rotates to
the load position ( RelayG on ).
By this time the trap is hot ( 180C )
so the sulfurmolecules are easily
flushed from the trap onto the col-
umn.
The column temperature remains
at 40C until theH2S peak has
eluted ( 5minutes ) then ramps up
to clean out the column and elute
any other sulfurmoleculeswith
higher boiling points ( CS2 etc ).
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