User`s guide

Theory of Thermal Desorption
312
adsorbent to strong adsorbent. Any volatiles purged out of the weak
adsorbent will land on the strong adsorbent (see the following figure
for the addition of the ISV2 solution valve). For the strong
adsorbent, in this analysis, a hydrophobic adsorbent should be
chosen, which allows water to pass out to the desorb vent without
losing the volatile compounds. Heated purge can be used to more
efficiently perform the reverse dry purge.
Figure 92 Reverse Dry Purge
Transfer Line
to GC
Sample
Tube
SV1
Desorb Supply
SV4
Outlet
Split
SV3
Desorb
Vent
Leak
Pressure
Frit
Desorb
Flow
Vent
S
ample Loa
d
and Reverse
Purge Vent
Suppl
y
SV2
Carrier
Supply
A
B
Inlet Split,
Outlet Split,
Tube Condition Vent
Standard
SVX
Loop Vent
Valve D
Position B
SV5
Inlet Split
2
3
4
5
6
1
Valve A
Position B
2
3
4
1
Trap
SV2
Load Vent
PPC-SVX
Frit Bypass
Transfer Line
to GC
Sample
Tube
SV1
Desorb Supply
SV4
Outlet
Split
SV3
Desorb
Vent
Leak
Pressure
S
ample Loa
d
and Reverse
Purge Vent
Supply
SV2
Carrier
Supply
A
B
Inlet Split,
Outlet Split,
Tube Condition Vent
Standard
SVX
Loop Vent
Valve D
Position B
SV5
Inlet Split
2
3
4
5
6
1
Valve A
Position B
2
3
4
1
Trap
SV2
Load Vent