5
Flowdirectionduring theChallenge
FlowdirectionduringDesorption
Adsorbent occupieda
3.7cmbed-length
(0.5cc
3
volume)
Glass Frit
Inlet of the tube
SSClip
Glasswool plug
Figure3. Drawingof thePackedAdsorbent Tube
Depicting theBedLengthof EachAdsorbent
GERSTELTDSAParameters
GERSTELMASter Software
SampleMode
Standard
FlowMode
Solvent Venting
Transfer Temp
275°C
PurgeTime
1.00min
Initial Temp
25°C
Initial Time
1.00min
Delay Time
1.75min
1
st
RampRate
60°C/min
Final Temp *
Final Time *
2
nd
RampRate
0°C
Final Temp -NA-
Final Time -NA-
Online
-NA-
GERSTELCIS-4 Inlet Parameters
GERSTELMASter Software HPChemstation – Inlet Screen
CryoCooling ON
Mode
Solvent Vent
Equilib Time 0.2min
Inlet Pressure 26.7psi
Initial Temp -150°C Total Flow 14.0mL/min
(Set-point)
Initial Time
0.10min Vent Flow 20mL/min
1st RampRate 12°C/sec Vent Pressure 26.9psi
Final Temp 350°C Until
0.00min
Final Time 3.00min Purge flow 10.0mL/min
to split vent
2
nd
RampRate 0°C
@
0.01min
Final Temp -NA-
Final Time -NA-
GasSaver
Not used
Cryo-FocusingTrapCIS-4 Inlet Liner (Physical Data)
Inlet Liner Type Standard Liner with notch (GC07540 10)
Adsorbent CarbotrapC* 20/40mesh
andGlassBeads 60mesh
(* adsorbent is at the notch)
GlassWool Type UntreatedGlassWool
Each adsorbent was
desorbed for a total of 6
minutes. To achieve this,
the following conditions
were used:
*Final Temp *Final Time
180°C
3.5min
300°C
1.5min
330°C
1.0min
HP-6890GCParameters
OvenProgram
Ramp 1
Final
Initial Initial
Ramp 1 Hold
Final Hold
Temp Hold Rate 1 Temp Time Rate 2 Temp Time
35°C 8.00min 5°C/min 100°C 0min 15°C/min 230°C 8min
CapillaryColumn:
60meter x 0.25mm ID, 3.0µm filmSPB-1
(Available fromSupelco as a custom product).
ColumnParameters
Set-Point
Pressure
24.0psi
ColumnFlow
1.5mL/min
Avg. Velocity
31cm/sec
HP-5973MSD
ScanParameters
MSDTemperatureZones
LowMass
35amu MSQuad
150°C
HighMass
269amu MSSource
230°C
Threshold
200
MS Interface
230°C
EmVoltage
1576 Solvent Delay
0.00min
SamplingRate 2
3
Adsorbent Tube Injector System
Parameters
Block Temperature 65°C
Glassware
10mL InjectionGlasswarew/septa port
Transfer Gas
Nitrogen
Gas FlowRate
50mL/min
Transfer Time
4minutes
Transfer Volume
0.2 liters
SupplyPressure
50psig
Note: The actual adsorbent tube is not heated.
Sequenceof Events
Preparationof theAdsorbents
We packed each of the adsorbents into a 4mm ID x 6mmOD x
178mm frittedglass tube, basedona fixed volumeof 0.5cc.We
constructed a 0.5cc vessel by cutting a 3.7cm length of tubing
from a representative empty glass tube. We packed the adsor-
bent into the vessel and vibrated it to assure we obtained a
consistentvolumeof theadsorbent.We thenpoured thecontents
of the0.5ccvessel into theempty tube.We insertedasmall plug
of untreatedglasswool on topof theadsorbent bedalongwitha
small stainlesssteel clip toprovideadditional support tokeep the
adsorbent inplace.We thermallyconditionedeachof thepacked
adsorbent tubes for eight hours with a continuous flow of clean
nitrogen.
Figure 3
illustrates the packed adsorbent tube.
Table
1
lists the actual bedweights of each tube and the conditioning
temperatures used for each adsorbent. Further details on our
tubepackingprocedurecanbe found in theQuestions&Answers
section.
Table3. OperatingConditions
