28
(8) Go back to step (3) and repeat for each solvent in the list.
(9) After cleaning the chamber, the cell cap can be removed. A screw from the cap
can be threaded into the piston to remove it from the chamber (Figure 12). The seal
(MCCS) should be removed and discarded.
(10) Wipe out any additional trace material with a cotton swab. The mixing chamber
is ready for the next sample.
RESETTING THE SYSTEM FOR THE NEXT SAMPLE
The following guidelines are for resetting the system; primarily resetting the internal
gas booster reservoir separator piston to the proper position for the next sample.
This method can be used to confirm that the separator piston has been moved to the
fully reset position.
At this point the reservoir pressure and syringe pump pressure are probably well
above the CO
2
gas cylinder outlet pressure (1,800 psi). Before the reservoir can be
recharged the pressure in both the reservoir and syringe pump should be below this
level. All the system valves should be closed at this point.
(1)
Open
the
HP ALKANE TO BOOSTER
valve and the
OUTLET
valve on the
syringe pump. This will allow excess alkane to flow back into the syringe pump.
The reservoir pressure may be higher than the syringe pump so there may be a
jump in the pressure reported by the syringe pump.
Figure 15: Removing the piston